man perltidy () - a perl script indenter and reformatter
NAME
perltidy - a perl script indenter and reformatter
SYNOPSIS
perltidy [ options ] file1 file2 file3 ...
(output goes to file1.tdy, file2.tdy, file3.tdy, ...)
perltidy [ options ] file1 -o outfile
perltidy [ options ] file1 -st >outfile
perltidy [ options ] <infile >outfile
DESCRIPTION
Perltidy reads a perl script and writes an indented, reformatted script.
Many users will find enough information in EXAMPLES to get started. New users may benefit from the short tutorial which can be found at http://perltidy.sourceforge.net/tutorial.html
A convenient aid to systematically defining a set of style parameters can be found at http://perltidy.sourceforge.net/stylekey.html
Perltidy can produce output on either of two modes, depending on the existence of an -html flag. Without this flag, the output is passed through a formatter. The default formatting tries to follow the recommendations in perlstyle(1), but it can be controlled in detail with numerous input parameters, which are described in FORMATTING OPTIONS.
When the -html flag is given, the output is passed through an HTML formatter which is described in HTML OPTIONS.
EXAMPLES
perltidy somefile.pl
This will produce a file somefile.pl.tdy containing the script reformatted using the default options, which approximate the style suggested in perlstyle(1). Perltidy never changes the input file.
perltidy *.pl
Execute perltidy on all .pl files in the current directory with the default options. The output will be in files with an appended .tdy extension. For any file with an error, there will be a file with extension .ERR.
perltidy -b file1.pl file2.pl
Modify file1.pl and file1.pl in place, and backup the originals to file1.pl.bak and file2.pl.bak. If file1.pl.bak and/or file2.pl.bak already exist, they will be overwritten.
perltidy -gnu somefile.pl
Execute perltidy on file somefile.pl with a style which approximates the GNU Coding Standards for C programs. The output will be somefile.pl.tdy.
perltidy -i=3 somefile.pl
Execute perltidy on file somefile.pl, with 3 columns for each level of indentation (-i=3) instead of the default 4 columns. There will not be any tabs in the reformatted script, except for any which already exist in comments, pod documents, quotes, and here documents. Output will be somefile.pl.tdy.
perltidy -i=3 -et=8 somefile.pl
Same as the previous example, except that leading whitespace will be entabbed with one tab character per 8 spaces.
perltidy -ce -l=72 somefile.pl
Execute perltidy on file somefile.pl with all defaults except use cuddled elses (-ce) and a maximum line length of 72 columns (-l=72) instead of the default 80 columns.
perltidy -g somefile.pl
Execute perltidy on file somefile.pl and save a log file somefile.pl.LOG which shows the nesting of braces, parentheses, and square brackets at the start of every line.
perltidy -html somefile.pl
This will produce a file somefile.pl.html containing the script with html markup. The output file will contain an embedded style sheet in the <HEAD> section which may be edited to change the appearance.
perltidy -html -css=mystyle.css somefile.pl
This will produce a file somefile.pl.html containing the script with html markup. This output file will contain a link to a separate style sheet file mystyle.css. If the file mystyle.css does not exist, it will be created. If it exists, it will not be overwritten.
perltidy -html -pre somefile.pl
Write an html snippet with only the PRE section to somefile.pl.html. This is useful when code snippets are being formatted for inclusion in a larger web page. No style sheet will be written in this case.
perltidy -html -ss >mystyle.css
Write a style sheet to mystyle.css and exit.
perltidy -html -frm mymodule.pm
Write html with a frame holding a table of contents and the source code. The output files will be mymodule.pm.html (the frame), mymodule.pm.toc.html (the table of contents), and mymodule.pm.src.html (the source code).
OPTIONS - OVERVIEW
The entire command line is scanned for options, and they are processed before any files are processed. As a result, it does not matter whether flags are before or after any filenames. However, the relative order of parameters is important, with later parameters overriding the values of earlier parameters.
For each parameter, there is a long name and a short name. The short names are convenient for keyboard input, while the long names are self-documenting and therefore useful in scripts. It is customary to use two leading dashes for long names, but one may be used.
Most parameters which serve as on/off flags can be negated with a leading n (for the short name) or a leading no or no- (for the long name). For example, the flag to outdent long quotes is is -olq or --outdent-long-quotes. The flag to skip this is -nolq or --nooutdent-long-quotes or --no-outdent-long-quotes.
Options may not be bundled together. In other words, options -q and -g may NOT be entered as -qg.
Option names may be terminated early as long as they are uniquely identified. For example, instead of -dump-token-types, it would be sufficient to enter -dump-tok, or even -dump-t, to uniquely identify this command.
I/O control
The following parameters concern the files which are read and written.
- -h, --help
- Show summary of usage and exit.
- -o=filename, --outfile=filename
- Name of the output file (only if a single input file is being processed). If no output file is specified, and output is not redirected to the standard output (see -st), the output will go to filename.tdy. [Note: - does not redirect to standard output. Use -st instead.]
- -st, --standard-output
-
Perltidy must be able to operate on an arbitrarily large number of files
in a single run, with each output being directed to a different output
file. Obviously this would conflict with outputting to the single
standard output device, so a special flag, -st, is required to
request outputting to the standard output. For example,
perltidy somefile.pl -st >somefile.new.pl
This option may only be used if there is just a single input file. The default is -nst or -nostandard-output. - -se, --standard-error-output
- If perltidy detects an error when processing file somefile.pl, its default behavior is to write error messages to file somefile.pl.ERR. Use -se to cause all error messages to be sent to the standard error output stream instead. This directive may be negated with -nse. Thus, you may place -se in a .perltidyrc and override it when desired with -nse on the command line.
- -oext=ext, --output-file-extension=ext
- Change the extension of the output file to be ext instead of the default tdy (or html in case the --html option is used). See Specifying File Extensions.
- -opath=path, --output-path=path
-
When perltidy creates a filename for an output file, by default it merely
appends an extension to the path and basename of the input file. This
parameter causes the path to be changed to path instead.
The path should end in a valid path separator character, but perltidy will try
to add one if it is missing.
For example
perltidy somefile.pl -opath=/tmp/
will produce /tmp/somefile.pl.tdy. Otherwise, somefile.pl.tdy will appear in whatever directory contains somefile.pl. If the path contains spaces, it should be placed in quotes. This parameter will be ignored if output is being directed to standard output, or if it is being specified explicitly with the -o=s parameter. - -b, --backup-and-modify-in-place
- Modify the input file or files in-place and save the original with the extension .bak. Any existing .bak file will be deleted. See next item for changing the default backup extension. A -b flag will be ignored if input is from standard input, or if the -html flag is set.
- -bext=ext, --backup-file-extension=ext
- Change the extension of the backup file to be something other than the default .bak. See Specifying File Extensions.
- -w, --warning-output
- Setting -w causes any non-critical warning messages to be reported as errors. These include messages about possible pod problems, possibly bad starting indentation level, and cautions about indirect object usage. The default, -nw or --nowarning-output, is not to include these warnings.
- -q, --quiet
-
Deactivate error messages and syntax checking (for running under
an editor).
For example, if you use a vi-style editor, such as vim, you may execute
perltidy as a filter from within the editor using something like
:n1,n2!perltidy -q
where CWn1,n2 represents the selected text. Without the -q flag, any error message may mess up your screen, so be prepared to use your undo key. - -log, --logfile
- Save the .LOG file, which has many useful diagnostics. Perltidy always creates a .LOG file, but by default it is deleted unless a program bug is suspected. Setting the -log flag forces the log file to be saved.
- -g=n, --logfile-gap=n
- Set maximum interval between input code lines in the logfile. This purpose of this flag is to assist in debugging nesting errors. The value of CWn is optional. If you set the flag -g without the value of CWn, it will be taken to be 1, meaning that every line will be written to the log file. This can be helpful if you are looking for a brace, paren, or bracket nesting error. Setting -g also causes the logfile to be saved, so it is not necessary to also include -log. If no -g flag is given, a value of 50 will be used, meaning that at least every 50th line will be recorded in the logfile. This helps prevent excessively long log files. Setting a negative value of CWn is the same as not setting -g at all.
- -npro --noprofile
- Ignore any .perltidyrc command file. Normally, perltidy looks first in your current directory for a .perltidyrc file of parameters. (The format is described below). If it finds one, it applies those options to the initial default values, and then it applies any that have been defined on the command line. If no .perltidyrc file is found, it looks for one in your home directory. If you set the -npro flag, perltidy will not look for this file.
- -pro=filename or --profile=filename
-
To simplify testing and switching .perltidyrc files, this command may be
used to specify a configuration file which will override the default
name of .perltidyrc. There must not be a space on either side of the
'=' sign. For example, the line
perltidy -pro=testcfg
would cause file testcfg to be used instead of the default .perltidyrc. - -opt, --show-options
- Write a list of all options used to the .LOG file. Please see --dump-options for a simpler way to do this.
- -f, --force-read-binary
- Force perltidy to process binary files. To avoid producing excessive error messages, perltidy skips files identified by the system as non-text. However, valid perl scripts containing binary data may sometimes be identified as non-text, and this flag forces perltidy to process them.
FORMATTING OPTIONS
Basic Options
- -l=n, --maximum-line-length=n
- The default maximum line length is n=80 characters. Perltidy will try to find line break points to keep lines below this length. However, long quotes and side comments may cause lines to exceed this length. Setting -l=0 is equivalent to setting -l=(a large number).
- -i=n, --indent-columns=n
- Use n columns per indentation level (default n=4).
- tabs
- Using tab characters will almost certainly lead to future portability and maintenance problems, so the default and recommendation is not to use them. For those who prefer tabs, however, there are two different options. Except for possibly introducing tab indentation characters, as outlined below, perltidy does not introduce any tab characters into your file, and it removes any tabs from the code (unless requested not to do so with -fws). If you have any tabs in your comments, quotes, or here-documents, they will remain.
- -et=n, --entab-leading-whitespace
- This flag causes each n initial space characters to be replaced by one tab character. Note that the integer n is completely independent of the integer specified for indentation parameter, -i=n.
- -t, --tabs
- This flag causes one leading tab character to be inserted for each level of indentation. Certain other features are incompatible with this option, and if these options are also given, then a warning message will be issued and this flag will be unset. One example is the -lp option.
- -syn, --check-syntax
- This flag causes perltidy to run CWperl -c -T to check syntax of input and output. (To change the flags passed to perl, see the next item, -pscf). The results are written to the .LOG file, which will be saved if an error is detected in the output script. The output script is not checked if the input script has a syntax error. Perltidy does its own checking, but this option employs perl to get a second opinion. If perl reports errors in the input file, they will not be reported in the error output unless the -warning-output flag is given. The default is not to do this type of syntax checking (although perltidy will still do as much self-checking as possible). The reason is that it causes all code in BEGIN blocks to be executed, for all modules being used, and this opens the door to security issues and infinite loops when running perltidy.
- -pscf=s, -perl-syntax-check-flags=s
- When perl is invoked to check syntax, the normal flags are CW-c -T. In addition, if the -x flag is given to perltidy, then perl will also be passed a -x flag. It should not normally be necessary to change these flags, but it can be done with the -pscf=s flag. For example, if the taint flag, CW-T, is not wanted, the flag could be set to be just -pscf=-c. Perltidy will pass your string to perl with the exception that it will add a -c and -x if appropriate. The .LOG file will show exactly what flags were passed to perl.
- -io, --indent-only
- This flag is used to deactivate all formatting and line break changes. When it is in effect, the only change to the script will be indentation. And any flags controlling whitespace and newlines will be ignored. You might want to use this if you are perfectly happy with your whitespace and line breaks, and merely want perltidy to handle the indentation. (This also speeds up perltidy by well over a factor of two, so it might be useful when perltidy is merely being used to help find a brace error in a large script). Setting this flag is equivalent to setting --freeze-newlines and --freeze-whitespace.
- -ole=s, --output-line-ending=s
- where s=CWwin, CWdos, CWunix, or CWmac. This flag tells perltidy to output line endings for a specific system. Normally, perltidy writes files with the line separator character of the host system. The CWwin and CWdos flags have an identical result. NOTE: This only works under unix-like systems and is ignored under other systems.
- -ple, --preserve-line-endings
- This flag tells perltidy to write its output files with the same line endings as the input file, if possible. It should work for dos, unix, and mac line endings. It will only work if perltidy input comes from a filename (rather than stdin, for example). If perltidy has trouble determining the input file line ending, it will revert to the default behavior of using the line ending of the host system. NOTE: This only works under unix-like systems and is ignored under other systems.
Code Indentation Control
- -ci=n, --continuation-indentation=n
-
Continuation indentation is extra indentation spaces applied when
a long line is broken. The default is n=2, illustrated here:
my $level = # -ci=2 ( $max_index_to_go >= 0 ) ? $levels_to_go[0] : $last_output_level;
The same example, with n=0, is a little harder to read:my $level = # -ci=0 ( $max_index_to_go >= 0 ) ? $levels_to_go[0] : $last_output_level;
The value given to -ci is also used by some commands when a small space is required. Examples are commands for outdenting labels, -ola, and control keywords, -okw. When default values are not used, it is suggested that the value n given with -ci=n be no more than about one-half of the number of spaces assigned to a full indentation level on the -i=n command. - -sil=n --starting-indentation-level=n
- By default, perltidy examines the input file and tries to determine the starting indentation level. While it is often zero, it may not be zero for a code snippet being sent from an editing session. If the default method does not work correctly, or you want to change the starting level, use -sil=n, to force the starting level to be n.
- List indentation using -lp, --line-up-parentheses
-
By default, perltidy indents lists with 4 spaces, or whatever value
is specified with -i=n. Here is a small list formatted in this way:
# perltidy (default) @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' );Use the -lp flag to add extra indentation to cause the data to begin past the opening parentheses of a sub call or list, or opening square bracket of an anonymous array, or opening curly brace of an anonymous hash. With this option, the above list would become:# perltidy -lp @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' );If the available line length (see -l=n ) does not permit this much space, perltidy will use less. For alternate placement of the closing paren, see the next section. This option has no effect on code BLOCKS, such as if/then/else blocks, which always use whatever is specified with -i=n. Also, the existence of line breaks and/or block comments between the opening and closing parens may cause perltidy to temporarily revert to its default method. Note: The -lp option may not be used together with the -t tabs option. It may, however, be used with the -et=n tab method. In addition, any parameter which significantly restricts the ability of perltidy to choose newlines will conflict with -lp and will cause -lp to be deactivated. These include -io, -fnl, -nanl, and -ndnl. The reason is that the -lp indentation style can require the careful coordination of an arbitrary number of break points in hierarchical lists, and these flags may prevent that. - -cti=n, --closing-token-indentation
-
The -cti=n flag controls the indentation of a line beginning with
a CW), CW], or a non-block CW}. Such a line receives:
-cti = 0 no extra indentation (default) -cti = 1 extra indentation such that the closing token aligns with its opening token. -cti = 2 one extra indentation level if the line looks like: ); or ]; or };The flags -cti=1 and -cti=2 work well with the -lp flag (previous section).# perltidy -lp -cti=1 @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' );# perltidy -lp -cti=2 @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' );These flags are merely hints to the formatter and they may not always be followed. In particular, if -lp is not being used, the indentation for cti=1 is constrained to be no more than one indentation level. If desired, this control can be applied independently to each of the closing container token types. In fact, -cti=n is merely an abbreviation for -cpi=n -csbi=n -cbi=n, where: -cpi or -closing-paren-indentation controls )'s, -csbi or -closing-square-bracket-indentation controls ]'s, -cbi or -closing-brace-indentation controls non-block }'s. - -icp, --indent-closing-paren
- The -icp flag is equivalent to -cti=2, described in the previous section. The -nicp flag is equivalent -cti=0. They are included for backwards compatability.
- -icb, --indent-closing-brace
-
The -icb option leaves a brace which terminates a code block
indented with the same indentation as the previous line. For example,
if ($task) { yyy(); } # -icb else { zzz(); }The default is not to do this, indicated by -nicb. - -olq, --outdent-long-quotes
- When -olq is set, lines which is a quoted string longer than the value maximum-line-length will have their indentation removed to make them more readable. This is the default. To prevent such out-denting, use -nolq or --nooutdent-long-lines.
- -oll, --outdent-long-lines
- This command is equivalent to --outdent-long-quotes and --outdent-long-comments, and it is included for compatibility with previous versions of perltidy. The negation of this also works, -noll or --nooutdent-long-lines, and is equivalent to setting -nolq and -nolc.
- Outdenting Labels: -ola, --outdent-labels
-
This command will cause labels to be outdented by 2 spaces (or whatever -ci
has been set to), if possible. This is the default. For example:
my $i; LOOP: while ( $i = <FOTOS> ) { chomp($i); next unless $i; fixit($i); }Use -nola to not outdent labels. - Outdenting Keywords
- -okw, --outdent-keywords
-
The command -okw will will cause certain leading control keywords to
be outdented by 2 spaces (or whatever -ci has been set to), if
possible. By default, these keywords are CWredo, CWnext, CWlast,
CWgoto, and CWreturn. The intention is to make these control keywords
easier to see. To change this list of keywords being outdented, see
the next section.
For example, using CWperltidy -okw on the previous example gives:
my $i; LOOP: while ( $i = <FOTOS> ) { chomp($i); next unless $i; fixit($i); }The default is not to do this. - Specifying Outdented Keywords: -okwl=string, --outdent-keyword-list=string
- This command can be used to change the keywords which are outdented with the -okw command. The parameter string is a required list of perl keywords, which should be placed in quotes if there are more than one. By itself, it does not cause any outdenting to occur, so the -okw command is still required. For example, the commands CW-okwl="next last redo goto" -okw will cause those four keywords to be outdented. It is probably simplest to place any -okwl command in a .perltidyrc file.
Whitespace Control
Whitespace refers to the blank space between variables, operators, and other code tokens.
- -fws, --freeze-whitespace
- This flag causes your original whitespace to remain unchanged, and causes the rest of the whitespace commands in this section, the Code Indentation section, and the Comment Control section to be ignored.
- Tightness of curly braces, parentheses, and square brackets.
-
Here the term tightness will mean the closeness with which
pairs of enclosing tokens, such as parentheses, contain the quantities
within. A numerical value of 0, 1, or 2 defines the tightness, with
0 being least tight and 2 being most tight. Spaces within containers
are always symmetric, so if there is a space after a CW( then there
will be a space before the corresponding CW).
The -pt=n or --paren-tightness=n parameter controls the space within
parens. The example below shows the effect of the three possible
values, 0, 1, and 2:
if ( ( my $len_tab = length( $tabstr ) ) > 0 ) { # -pt=0 if ( ( my $len_tab = length($tabstr) ) > 0 ) { # -pt=1 (default) if ((my $len_tab = length($tabstr)) > 0) { # -pt=2When n is 0, there is always a space to the right of a '(' and to the left of a ')'. For n=2 there is never a space. For n=1, the default, there is a space unless the quantity within the parens is a single token, such as an identifier or quoted string. Likewise, the parameter -sbt=n or --square-bracket-tightness=n controls the space within square brackets, as illustrated below.$width = $col[ $j + $k ] - $col[ $j ]; # -sbt=0 $width = $col[ $j + $k ] - $col[$j]; # -sbt=1 (default) $width = $col[$j + $k] - $col[$j]; # -sbt=2
Curly braces which do not contain code blocks are controlled by the parameter -bt=n or --brace-tightness=n.$obj->{ $parsed_sql->{ 'table' }[0] }; # -bt=0 $obj->{ $parsed_sql->{'table'}[0] }; # -bt=1 (default) $obj->{$parsed_sql->{'table'}[0]}; # -bt=2And finally, curly braces which contain blocks of code are controlled by the parameter -bbt=n or --block-brace-tightness=n as illustrated in the example below.%bf = map { $_ => -M $_ } grep { /\.deb$/ } dirents '.'; # -bbt=0 (default) %bf = map { $_ => -M $_ } grep {/\.deb$/} dirents '.'; # -bbt=1 %bf = map {$_ => -M $_} grep {/\.deb$/} dirents '.'; # -bbt=2 - -sts, --space-terminal-semicolon
-
Some programmers prefer a space before all terminal semicolons. The
default is for no such space, and is indicated with -nsts or
--nospace-terminal-semicolon.
$i = 1 ; # -sts $i = 1; # -nsts (default) - -sfs, --space-for-semicolon
-
Semicolons within for loops may sometimes be hard to see,
particularly when commas are also present. This option places spaces on
both sides of these special semicolons, and is the default. Use
-nsfs or --nospace-for-semicolon to deactivate it.
for ( @a = @$ap, $u = shift @a ; @a ; $u = $v ) { # -sfs (default) for ( @a = @$ap, $u = shift @a; @a; $u = $v ) { # -nsfs - -asc, --add-semicolons
- Setting -asc allows perltidy to add any missing optional semicolon at the end of a line which is followed by a closing curly brace on the next line. This is the default, and may be deactivated with -nasc or --noadd-semicolons.
- -dsm, --delete-semicolons
- Setting -dsm allows perltidy to delete extra semicolons which are simply empty statements. This is the default, and may be deactivated with -ndsm or --nodelete-semicolons. (Such semicolons are not deleted, however, if they would promote a side comment to a block comment).
- -aws, --add-whitespace
- Setting this option allows perltidy to add certain whitespace improve code readability. This is the default. If you do not want any whitespace added, but are willing to have some whitespace deleted, use -naws. (Use -fws to leave whitespace completely unchanged).
- -dws, --delete-old-whitespace
- Setting this option allows perltidy to remove some old whitespace between characters, if necessary. This is the default. If you do not want any old whitespace removed, use -ndws or --nodelete-old-whitespace.
- Detailed whitespace controls around tokens
-
For those who want more detailed control over the whitespace around
tokens, there are four parameters which can directly modify the default
whitespace rules built into perltidy for any token. They are:
-wls=s or --want-left-space=s,
-nwls=s or --nowant-left-space=s,
-wrs=s or --want-right-space=s,
-nwrs=s or --nowant-right-space=s.
These parameters are each followed by a quoted string, s, containing a
list of token types. No more than one of each of these parameters
should be specified, because repeating a command-line parameter
always overwrites the previous one before perltidy ever sees it.
To illustrate how these are used, suppose it is desired that there be no
space on either side of the token types = + - / *. The following two
parameters would specify this desire:
-nwls="= + - / *" -nwrs="= + - / *"
(Note that the token types are in quotes, and that they are separated by spaces). With these modified whitespace rules, the following line of math:$root = -$b + sqrt( $b * $b - 4. * $a * $c ) / ( 2. * $a );
becomes this:$root=-$b+sqrt( $b*$b-4.*$a*$c )/( 2.*$a );
These parameters should be considered to be hints to perltidy rather than fixed rules, because perltidy must try to resolve conflicts that arise between them and all of the other rules that it uses. One conflict that can arise is if, between two tokens, the left token wants a space and the right one doesn't. In this case, the token not wanting a space takes priority. It is necessary to have a list of all token types in order to create this type of input. Such a list can be obtained by the command -dump-token-types. - Space between keyword and opening paren
-
When an opening paren follows a keyword, no space is introduced after the
keyword, unless it is (by default) one of these:
my local our and or eq ne if else elsif until unless while for foreach return switch case given when
These defaults can be modified with two commands: -sak=s or --space-after-keyword=s adds keywords. -nsak=s or --nospace-after-keyword=s removes keywords. where s is a list of keywords (in quotes if necessary). For example,my ( $a, $b, $c ) = @_; # default my( $a, $b, $c ) = @_; # -nsak="my local our"
-tqw or --trim-qw provide the default behavior of trimming spaces around multi-line CWqw quotes and indenting them appropriately. -ntqw or --notrim-qw cause leading and trailing whitespace around multi-line CWqw quotes to be left unchanged. This option will not normally be necessary, but was added for testing purposes, because in some versions of perl, trimming CWqw quotes changes the syntax tree.
Comment Controls
Perltidy has a number of ways to control the appearance of both block comments and side comments. The term block comment here refers to a full-line comment, whereas side comment will refer to a comment which appears on a line to the right of some code.
- -ibc, --indent-block-comments
-
Block comments normally look best when they are indented to the same
level as the code which follows them. This is the default behavior, but
you may use -nibc to keep block comments left-justified. Here is an
example:
# this comment is indented (-ibc, default) if ($task) { yyy(); }The alternative is -nibc:# this comment is not indented (-nibc) if ($task) { yyy(); }See also the next item, -isbc, as well as -sbc, for other ways to have some indented and some outdented block comments. - -isbc, --indent-spaced-block-comments
- If there is no leading space on the line, then the comment will not be indented, and otherwise it may be. If both -ibc and -isbc are set, then -isbc takes priority.
- -olc, --outdent-long-comments
- When -olc is set, lines which are full-line (block) comments longer than the value maximum-line-length will have their indentation removed. The default is not to do this.
- -msc=n, --minimum-space-to-comment=n
- Side comments look best when lined up several spaces to the right of code. Perltidy will try to keep comments at least n spaces to the right. The default is n=4 spaces.
- -hsc, --hanging-side-comments
-
By default, perltidy tries to identify and align hanging side
comments, which are something like this:
my $IGNORE = 0; # This is a side comment # This is a hanging side comment # And so is thisA comment is considered to be a hanging side comment if (1) it immediately follows a line with a side comment, or another hanging side comment, and (2) there is some leading whitespace on the line. To deactivate this feature, use -nhsc or --nohanging-side-comments. If block comments are preceded by a blank line, or have no leading whitespace, they will not be mistaken as hanging side comments. - Closing Side Comments
-
A closing side comment is a special comment which perltidy can
automatically create and place after the closing brace of a code block.
They can be useful for code maintenance and debugging. The command
-csc (or -closing-side-comments) adds or updates closing side
comments. For example, here is a small code snippet
sub message { if ( !defined( $_[0] ) ) { print("Hello, World\n"); } else { print( $_[0], "\n" ); } }And here is the result of processing with CWperltidy -csc:sub message { if ( !defined( $_[0] ) ) { print("Hello, World\n"); } else { print( $_[0], "\n" ); } } ## end sub messageA closing side comment was added for CWsub message in this case, but not for the CWif and CWelse blocks, because they were below the 6 line cutoff limit for adding closing side comments. This limit may be changed with the -csci command, described below. The command -dcsc (or --delete-closing-side-comments) reverses this process and removes these comments. Several commands are available to modify the behavior of these two basic commands, -csc and -dcsc: - -csci=n, or -closing-side-comment-interval=n
-
where CWn is the minimum number of lines that a block must have in
order for a closing side comment to be added. The default value is
CWn=6. To illustrate:
# perltidy -csci=2 -csc sub message { if ( !defined( $_[0] ) ) { print("Hello, World\n"); } ## end if ( !defined( $_[0] )) else { print( $_[0], "\n" ); } ## end else [ if ( !defined( $_[0] )) } ## end sub messageNow the CWif and CWelse blocks are commented. However, now this has become very cluttered. - -cscp=string, or -closing-side-comment-prefix=string
- where string is the prefix used before the name of the block type. The default prefix, shown above, is CW## end. This string will be added to closing side comments, and it will also be used to recognize them in order to update, delete, and format them. Any comment identified as a closing side comment will be placed just a single space to the right of its closing brace.
- -cscl=string, or -closing-side-comment-list-string
-
where CWstring is a list of block types to be tagged with closing side
comments. By default, all code block types preceded by a keyword or
label (such as CWif, CWsub, and so on) will be tagged. The -cscl
command changes the default list to be any selected block types; see
Specifying Block Types.
For example, the following command
requests that only CWsub's, labels, CWBEGIN, and CWEND blocks be
affected by any -csc or -dcsc operation:
-cscl="sub : BEGIN END"
- -csct=n, or -closing-side-comment-maximum-text=n
- The text appended to certain block types, such as an CWif block, is whatever lies between the keyword introducing the block, such as CWif, and the opening brace. Since this might be too much text for a side comment, there needs to be a limit, and that is the purpose of this parameter. The default value is CWn=20, meaning that no additional tokens will be appended to this text after its length reaches 20 characters. Omitted text is indicated with CW.... (Tokens, including sub names, are never truncated, however, so actual lengths may exceed this). To illustrate, in the above example, the appended text of the first block is CW ( !defined( $_[0] ).... The existing limit of CWn=20 caused this text to be truncated, as indicated by the CW....
- -csce=n, or -closing-side-comment-else-flag=n
- The default, n=0, places the text of the opening CWif statement after any terminal CWelse. If n=2 is used, then each CWelsif is also given the text of the opening CWif statement. Also, an CWelse will include the text of a preceding CWelsif statement. Note that this may result some long closing side comments. If n=1 is used, the results will be the same as n=2 whenever the resulting line length is less than the maximum allowed.
- -cscw, or -closing-side-comment-warnings
- This parameter is intended to help make the initial transition to the use of closing side comments. It causes two things to happen if a closing side comment replaces an existing, different closing side comment: first, an error message will be issued, and second, the original side comment will be placed alone on a new specially marked comment line for later attention. The intent is to avoid clobbering existing hand-written side comments which happen to match the pattern of closing side comments. This flag should only be needed on the first run with -csc. Important Notes on Closing Side Comments:
- *
- Closing side comments are only placed on lines terminated with a closing brace. Certain closing styles, such as the use of cuddled elses (-ce), preclude the generation of some closing side comments.
- *
- Please note that adding or deleting of closing side comments takes place only through the commands -csc or -dcsc. The other commands, if used, merely modify the behavior of these two commands.
- *
- It is recommended that the -cscw flag be used along with -csc on the first use of perltidy on a given file. This will prevent loss of any existing side comment data which happens to have the csc prefix.
- *
- Once you use -csc, you should continue to use it so that any closing side comments remain correct as code changes. Otherwise, these comments will become incorrect as the code is updated.
- *
- If you edit the closing side comments generated by perltidy, you must also change the prefix to be different from the closing side comment prefix. Otherwise, your edits will be lost when you rerun perltidy with -csc. For example, you could simply change CW## end to be CW## End, since the test is case sensitive. You may also want to use the -ssc flag to keep these modified closing side comments spaced the same as actual closing side comments.
- *
- Temporarily generating closing side comments is a useful technique for exploring and/or debugging a perl script, especially one written by someone else. You can always remove them with -dcsc.
- Static Block Comments
- Static block comments are block comments with a special leading pattern, CW## by default, which will be treated slightly differently from other block comments. They effectively behave as if they had glue along their left and top edges, because they stick to the left edge and previous line when there is no blank spaces in those places. This option is particularly useful for controlling how commented code is displayed.
- -sbc, --static-block-comments
- When -sbc is used, a block comment with a special leading pattern, CW## by default, will be treated specially. Comments so identified are treated as follows:
- *
- If there is no leading space on the line, then the comment will not be indented, and otherwise it may be,
- *
- no new blank line will be inserted before such a comment, and
- *
-
such a comment will never become
a hanging side comment.
For example, assuming CW@month_of_year is
left-adjusted:
@month_of_year = ( # -sbc (default) 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', ## 'Dec', 'Nov' 'Nov', 'Dec');Without this convention, the above code would become@month_of_year = ( # -nsbc 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct',## 'Dec', 'Nov' 'Nov', 'Dec' );which is not as clear. The default is to use -sbc. This may be deactivated with -nsbc. - -sbcp=string, --static-block-comment-prefix=string
- This parameter defines the prefix used to identify static block comments when the -sbc parameter is set. The default prefix is CW##, corresponding to CW-sbcp=##. The first character must be a CW# symbol, since this must only match comments. As a simple example, to identify all comments as static block comments, one would use CW-sbcp=#. Please note that -sbcp merely defines the pattern used to identify static block comments; it will not be used unless the switch -sbc is set. Also, please be aware that this string is used in a perl regular expression which identifies these comments, so it must enable a valid regular expression to be formed.
- -osbc, --outdent-static-block-comments
- The command -osbc will will cause static block comments to be outdented by 2 spaces (or whatever -ci=n has been set to), if possible.
- Static Side Comments
- Static side comments are side comments with a special leading pattern. This option can be useful for controlling how commented code is displayed when it is a side comment.
- -ssc, --static-side-comments
- When -ssc is used, a side comment with a static leading pattern, which is CW## by default, will be be spaced only a single space from previous character, and it will not be vertically aligned with other side comments. The default is -nssc.
- -sscp=string, --static-side-comment-prefix=string
- This parameter defines the prefix used to identify static side comments when the -ssc parameter is set. The default prefix is CW##, corresponding to CW-sscp=##. Please note that -sscp merely defines the pattern used to identify static side comments; it will not be used unless the switch -ssc is set. Also, note that this string is used in a perl regular expression which identifies these comments, so it must enable a valid regular expression to be formed.
Line Break Control
- -fnl, --freeze-newlines
- If you do not want any changes to the line breaks in your script, set -fnl, and they will remain fixed, and the rest of the commands in this section and sections Controlling List Formatting, Retaining or Ignoring Existing Line Breaks, and Blank Line Control will be ignored. You may want to use -noll with this.
- -ce, --cuddled-else
-
Enable the cuddled else style, in which CWelse and CWelsif are
follow immediately after the curly brace closing the previous block.
The default is not to use cuddled elses, and is indicated with the flag
-nce or --nocuddled-else. Here is a comparison of the
alternatives:
if ($task) { yyy(); } else { # -ce zzz(); }if ($task) { yyy(); } else { # -nce (default) zzz(); } - -bl, --opening-brace-on-new-line
-
Use the flag -bl to place the opening brace on a new line:
if ( $input_file eq '-' ) # -bl { important_function(); }This flag applies to all structural blocks, including sub's (unless the -sbl flag is set see next item). The default style, -nbl, places an opening brace on the same line as the keyword introducing it. For example,if ( $input_file eq '-' ) { # -nbl (default) - -sbl, --opening-sub-brace-on-new-line
-
The flag -sbl can be used to override the value of -bl for
opening sub braces. For example,
perltidy -sbl
produces this result:sub message { if (!defined($_[0])) { print("Hello, World\n"); } else { print($_[0], "\n"); } }This flag is negated with -nsbl. If -sbl is not specified, the value of -bl is used. - -bli, --brace-left-and-indent
-
The flag -bli is the same as -bl but in addition it causes one
unit of continuation indentation ( see -ci ) to be placed before
an opening and closing block braces.
For example,
if ( $input_file eq '-' ) # -bli { important_function(); }By default, this extra indentation occurs for blocks of type: if, elsif, else, unless, for, foreach, sub, while, until, and also with a preceding label. The next item shows how to change this. - -blil=s, --brace-left-and-indent-list=s
- Use this parameter to change the types of block braces for which the -bli flag applies; see Specifying Block Types. For example, -blil='if elsif else' would apply it to only CWif/elsif/else blocks.
- -bar, --opening-brace-always-on-right
-
The default style, -nbl places the opening brace on a new
line if it does not fit on the same line as the opening keyword, like
this:
if ( $bigwasteofspace1 && $bigwasteofspace2 || $bigwasteofspace3 && $bigwasteofspace4 ) { big_waste_of_time(); }To force the opening brace to always be on the right, use the -bar flag. In this case, the above example becomesif ( $bigwasteofspace1 && $bigwasteofspace2 || $bigwasteofspace3 && $bigwasteofspace4 ) { big_waste_of_time(); }A conflict occurs if both -bl and -bar are specified. - Vertical tightness of non-block curly braces, parentheses, and square brackets.
- These parameters control what shall be called vertical tightness. Here are the main points:
- *
-
Opening tokens (except for block braces) are controlled by -vt=n, or
--vertical-tightness=n, where
-vt=0 always break a line after opening token (default). -vt=1 do not break unless this would produce more than one step in indentation in a line. -vt=2 never break a line after opening token - *
- You must also use the -lp flag when you use the -vt flag; the reason is explained below.
- *
-
Closing tokens (except for block braces) are controlled by -vtc=n, or
--vertical-tightness-closing=n, where
-vtc=0 always break a line before a closing token (default), -vtc=1 do not break before a closing token which is followed by a semicolon or another closing token, and is not in a list environment. -vtc=2 never break before a closing token.The rules for -vtc=1 are designed to maintain a reasonable balance between tightness and readability in complex lists. - *
- Different controls may be applied to to different token types, and it is also possible to control block braces; see below.
- *
-
Finally, please note that these vertical tightness flags are merely
hints to the formatter, and it cannot always follow them. Things which
make it difficult or impossible include comments, blank lines, blocks of
code within a list, and possibly the lack of the -lp parameter.
Also, these flags may be ignored for very small lists (2 or 3 lines in
length).
Here are some examples:
# perltidy -lp -vt=0 -vtc=0 %romanNumerals = ( one => 'I', two => 'II', three => 'III', four => 'IV', );# perltidy -lp -vt=1 -vtc=0 %romanNumerals = ( one => 'I', two => 'II', three => 'III', four => 'IV', );# perltidy -lp -vt=1 -vtc=1 %romanNumerals = ( one => 'I', two => 'II', three => 'III', four => 'IV', );The difference between -vt=1 and -vt=2 is shown here:# perltidy -lp -vt=1 $init->add( mysprintf( "(void)find_threadsv(%s);", cstring( $threadsv_names[ $op->targ ] ) ) );# perltidy -lp -vt=2 $init->add( mysprintf( "(void)find_threadsv(%s);", cstring( $threadsv_names[ $op->targ ] ) ) );With -vt=1, the line ending in CWadd( does not combine with the next line because the next line is not balanced. This can help with readability, but -vt=2 can be used to ignore this rule. The tightest, and least readable, code is produced with both CW-vt=2 and CW-vtc=2:# perltidy -lp -vt=2 -vtc=2 $init->add( mysprintf( "(void)find_threadsv(%s);", cstring( $threadsv_names[ $op->targ ] ) ) );Notice how the code in all of these examples collapses vertically as -vt increases, but the indentation remains unchanged. This is because perltidy implements the -vt parameter by first formatting as if -vt=0, and then simply overwriting one output line on top of the next, if possible, to achieve the desired vertical tightness. The -lp indentation style has been designed to allow this vertical collapse to occur, which is why it is required for the -vt parameter. The -vt=n and -vtc=n parameters apply to each type of container token. If desired, vertical tightness controls can be applied independently to each of the closing container token types. The parameters for controlling parentheses are -pvt=n or --paren-vertical-tightness=n, and -pcvt=n or --paren-vertical-tightness-closing=n. Likewise, the parameters for square brackets are -sbvt=n or --square-bracket-vertical-tightness=n, and -sbcvt=n or --square-bracket-vertical-tightness-closing=n. Finally, the parameters for controlling non-code block braces are -bvt=n or --brace-vertical-tightness=n, and -bcvt=n or --brace-vertical-tightness-closing=n. In fact, the parameter -vt=n is actually just an abbreviation for -pvt=n -bvt=n sbvt=n, and likewise -vtc=n is an abbreviation for -pvtc=n -bvtc=n sbvtc=n. - -bbvt=n or --block-brace-vertical-tightness=n
-
The -bbvt=n flag is just like the -vt=n flag but applies
to opening code block braces.
-bbvt=0 break after opening block brace (default). -bbvt=1 do not break unless this would produce more than one step in indentation in a line. -bbvt=2 do not break after opening block brace.It is necessary to also use either -bl or -bli for this to work, because, as with other vertical tightness controls, it is implemented by simply overwriting a line ending with an opening block brace with the subsequent line. For example:# perltidy -bli -bbvt=0 if ( open( FILE, "< $File" ) ) { while ( $File = <FILE> ) { $In .= $File; $count++; } close(FILE); }# perltidy -bli -bbvt=1 if ( open( FILE, "< $File" ) ) { while ( $File = <FILE> ) { $In .= $File; $count++; } close(FILE); }By default this applies to blocks associated with keywords if, elsif, else, unless, for, foreach, sub, while, until, and also with a preceding label. This can be changed with the parameter -bbvtl=string, or --block-brace-vertical-tightness-list=string, where string is a space-separated list of block types. For more information on the possible values of this string, see Specifying Block Types For example, if we want to just apply this style to CWif, CWelsif, and CWelse blocks, we could use CWperltidy -bli -bbvt -bbvtl='if elsif else'. There is no vertical tightness control for closing block braces; with the exception of one-line blocks, they will normally remain on a separate line. - -dnl, --delete-old-newlines
- By default, perltidy first deletes all old line break locations, and then it looks for good break points to match the desired line length. Use -ndnl or --nodelete-old-newlines to force perltidy to retain all old line break points.
- -anl, --add-newlines
- By default, perltidy will add line breaks when necessary to create continuations of long lines and to improve the script appearance. Use -nanl or -noadd-newlines to prevent any new line breaks. This flag does not prevent perltidy from eliminating existing line breaks; see -freeze-newlines to completely prevent changes to line break points.
- Controlling whether perltidy breaks before or after operators
-
Two command line parameters provide some control over whether
a line break should be before or after specific token types.
-wba=s or --want-break-after=s, and
-wbb=s or --want-break-before=s.
These parameters are each followed by a quoted string, s, containing
a list of token types (separated only by spaces). No more than one of each
of these parameters should be specified, because repeating a
command-line parameter always overwrites the previous one before
perltidy ever sees it.
By default, perltidy breaks after these token types:
% + - * / x != == >= <= =~ !~ < > | & >= <
= **= += *= &= <<= &&= -= /= |= >>= ||= .= %= ^= x=
And perltidy breaks before these token types by default:
. << >> -> && ||
To illustrate, to cause a break after a concatenation operator, CW'.',
rather than before it, the command line would be
-wba="."
As another example, the following command would cause a break before math operators CW'+', CW'-', CW'/', and CW'*':-wbb="+ - / *"
These commands should work well for most of the token types that perltidy uses (use --dump-token-types for a list). However, for a few token types there may be conflicts with hardwired logic which cause unexpected results. One example is curly braces, which should be controlled with the parameter bl provided for that purpose.
Controlling List Formatting
Perltidy attempts to place comma-separated arrays of values in tables which look good. Its default algorithms usually work well, and they have been improving with each release, but several parameters are available to control list formatting.
- -boc, --break-at-old-comma-breakpoints
-
This flag tells perltidy to try to break at all old commas. This is not
the default. Normally, perltidy makes a best guess at list formatting,
and seldom uses old comma breakpoints. Usually this works well,
but consider:
my @list = (1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1,);The default formatting will flatten this down to one line:# perltidy (default) my @list = ( 1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, );which hides the structure. Using -boc, plus additional flags to retain the original style, yields# perltidy -boc -lp -pt=2 -vt=1 -vtc=1 my @list = (1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1,);A disadvantage of this flag is that all tables in the file must already be nicely formatted. - -mft=n, --maximum-fields-per-table=n
-
If the computed number of fields for any table exceeds n, then it
will be reduced to n. The default value for n is a large number,
40. While this value should probably be left unchanged as a general
rule, it might be used on a small section of code to force a list to
have a particular number of fields per line, and then either the -boc
flag could be used to retain this formatting, or a single comment could
be introduced somewhere to freeze the formatting in future applications
of perltidy.
# perltidy -mft=2 @month_of_year = ( 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ); - -cab=n, --comma-arrow-breakpoints=n
-
A comma which follows a comma arrow, '=>', requires special
consideration. In a long list, it is common to break at all such
commas. This parameter can be used to control how perltidy breaks at
these commas. (However, it will have no effect if old comma breaks are
being forced because -boc is used). The possible values of n are:
n=0 break at all commas after => n=1 stable: break at all commas after => unless this would break an existing one-line container (default) n=2 break at all commas after =>, but try to form the maximum maximum one-line container lengths n=3 do not treat commas after => specially at allFor example, given the following single line, perltidy by default will not add any line breaks because it would break the existing one-line container:bless { B => $B, Root => $Root } => $package;Using -cab=0 will force a break after each comma-arrow item:# perltidy -cab=0: bless { B => $B, Root => $Root } => $package;If perltidy is subsequently run with this container broken, then by default it will break after each '=>' because the container is now broken. To reform a one-line container, the parameter -cab=2 would be needed. The flag -cab=3 can be used to prevent these commas from being treated specially. In this case, an item such as 01 => 31 is treated as a single item in a table. The number of fields in this table will be determined by the same rules that are used for any other table. Here is an example.# perltidy -cab=3 my %last_day = ( "01" => 31, "02" => 29, "03" => 31, "04" => 30, "05" => 31, "06" => 30, "07" => 31, "08" => 31, "09" => 30, "10" => 31, "11" => 30, "12" => 31 );
Retaining or Ignoring Existing Line Breaks
Several additional parameters are available for controlling the extent to which line breaks in the input script influence the output script. In most cases, the default parameter values are set so that, if a choice is possible, the output style follows the input style. For example, if a short logical container is broken in the input script, then the default behavior is for it to remain broken in the output script.
Most of the parameters in this section would only be required for a one-time conversion of a script from short container lengths to longer container lengths. The opposite effect, of converting long container lengths to shorter lengths, can be obtained by temporarily using a short maximum line length.
- -bol, --break-at-old-logical-breakpoints
- By default, if a logical expression is broken at a CW&&, CW||, CWand, or CWor, then the container will remain broken. Also, breaks at internal keywords CWif and CWunless will normally be retained. To prevent this, and thus form longer lines, use -nbol.
- -bok, --break-at-old-keyword-breakpoints
- By default, perltidy will retain a breakpoint before keywords which may return lists, such as CWsort and <map>. This allows chains of these operators to be displayed one per line. Use -nbok to prevent retaining these breakpoints.
- -bot, --break-at-old-trinary-breakpoints
- By default, if a conditional (trinary) operator is broken at a CW:, then it will remain broken. To prevent this, and thereby form longer lines, use -nbot.
- -iob, --ignore-old-breakpoints
- Use this flag to tell perltidy to ignore existing line breaks to the maximum extent possible. This will tend to produce the longest possible containers, regardless of type, which do not exceed the line length limit.
Blank Line Control
Blank lines can improve the readability of a script if they are carefully placed. Perltidy has several commands for controlling the insertion, retention, and removal of blank lines.
- -bbc, --blanks-before-comments
- A blank line will be introduced before a full-line comment. This is the default. Use -nbbc or --noblanks-before-comments to prevent such blank lines from being introduced.
- -bbs, --blanks-before-subs
- A blank line will be introduced before a sub definition, unless it is a one-liner or preceded by a comment. A blank line will also be introduced before a package statement and a BEGIN and END block. This is the default. The intention is to help display the structure of a program by setting off certain key sections of code. This is negated with -nbbs or --noblanks-before-subs.
- -bbb, --blanks-before-blocks
- A blank line will be introduced before blocks of coding delimited by for, foreach, while, until, and if, unless, in the following circumstances:
- *
- The block is not preceded by a comment.
- *
- The block is not a one-line block.
- *
- The number of consecutive non-blank lines at the current indentation depth is at least -lbl (see next section). This is the default. The intention of this option is to introduce some space within dense coding. This is negated with -nbbb or --noblanks-before-blocks.
- -lbl=n --long-block-line-count=n
- This controls how often perltidy is allowed to add blank lines before certain block types (see previous section). The default is 8. Entering a value of 0 is equivalent to entering a very large number.
- -mbl=n --maximum-consecutive-blank-lines=n
- This parameter specifies the maximum number of consecutive blank lines in the output script. The default is n=1. If the input file has more than n consecutive blank lines, the number will be reduced to n. (This obviously does not apply to pod sections, here-documents, and quotes).
- -sob, --swallow-optional-blank-lines
- All blank lines not required by the above flags, -bbb, -bbs, and -bbc, will be deleted. (But essential blank lines above pod documents will be retained). This is NOT the default.
- -nsob, --noswallow-optional-blank-lines
- Retain blank lines, including those which do not corresponding to flags -bbb, -bbs, and -bbc. This is the default. The number of blanks retained is subject to the limit imposed by --maximum-consecutive-blank-lines, however.
Styles
A style refers to a convenient collection of existing parameters.
- -gnu, --gnu-style
-
-gnu gives an approximation to the GNU Coding Standards (which do
not apply to perl) as they are sometimes implemented. At present, this
style overrides the default style with the following parameters:
-lp -bl -noll -pt=2 -bt=2 -sbt=2 -icp
Other Controls
- Deleting selected text
- Perltidy can selectively delete comments and/or pod documentation. The command -dac or --delete-all-comments will delete all comments and all pod documentation, leaving just code and any leading system control lines. The command -dp or --delete-pod will remove all pod documentation (but not comments). Two commands which remove comments (but not pod) are: -dbc or --delete-block-comments and -dsc or --delete-side-comments. (Hanging side comments will be deleted with block comments here.) The negatives of these commands also work, and are the defaults. When block comments are deleted, any leading 'hash-bang' will be retained. Also, if the -x flag is used, any system commands before a leading hash-bang will be retained (even if they are in the form of comments).
- Writing selected text to a file
- When perltidy writes a formatted text file, it has the ability to also send selected text to a file with a .TEE extension. This text can include comments and pod documentation. The command -tac or --tee-all-comments will write all comments and all pod documentation. The command -tp or --tee-pod will write all pod documentation (but not comments). The commands which write comments (but not pod) are: -tbc or --tee-block-comments and -tsc or --tee-side-comments. (Hanging side comments will be written with block comments here.) The negatives of these commands also work, and are the defaults.
- Using a .perltidyrc command file
-
If you use perltidy frequently, you probably won't be happy until you
create a .perltidyrc file to avoid typing commonly-used parameters.
Perltidy will first look in your current directory for a command file
named .perltidyrc. If it does not find one, it will continue looking
for one in other standard locations.
These other locations are system-dependent, and may be displayed with
the command CWperltidy -dpro. Under Unix systems, it will look for a
.perltidyrc file in the home directory, and then for a system-wide
file /usr/local/etc/perltidyrc, and then it will look for
/etc/perltidyrc. Note that these last two system-wide files do not
have a leading dot. Further system-dependent information will be found
in the INSTALL file distributed with perltidy.
This file is free format, and simply a list of parameters, just as they
would be entered on a command line. Any number of lines may be used,
with any number of parameters per line, although it may be easiest to
read with one parameter per line. Blank lines are ignored, and text
after a '#' is ignored to the end of a line.
Here is an example of a .perltidyrc file:
# This is a simple of a .perltidyrc configuration file # This implements a highly spaced style -se # errors to standard error output -w # show all warnings -bl # braces on new lines -pt=0 # parens not tight at all -bt=0 # braces not tight -sbt=0 # square brackets not tight
The parameters in the .perltidyrc file are installed first, so any parameters given on the command line will have priority over them. To avoid confusion, perltidy ignores any command in the .perltidyrc file which would cause some kind of dump and an exit. These are:-h -v -ddf -dln -dop -dsn -dtt -dwls -dwrs -ss
There are several options may be helpful in debugging a .perltidyrc file: - *
-
A very helpful command is --dump-profile or -dpro. It writes a
list of all configuration filenames tested to standard output, and
if a file is found, it dumps the content to standard output before
exiting. So, to find out where perltidy looks for its configuration
files, and which one if any it selects, just enter
perltidy -dpro
- *
- It may be simplest to develop and test configuration files with alternative names, and invoke them with -pro=filename on the command line. Then rename the desired file to .perltidyrc when finished.
- *
- The parameters in the .perltidyrc file can be switched off with the -npro option.
- *
- The commands -dump-options, -dump-defaults, -dump-long-names, and -dump-short-names, all described below, may all be helpful.
- Creating a new abbreviation
-
A special notation is available for use in a .perltidyrc file
for creating an abbreviation for a group
of options. This can be used to create a
shorthand for one or more styles which are frequently, but not always,
used. The notation is to group the options within curly braces which
are preceded by the name of the alias (without leading dashes), like this:
newword { -opt1 -opt2 }where newword is the abbreviation, and opt1, etc, are existing parameters or other abbreviations. The main syntax requirement is that the new abbreviation must begin on a new line. Space before and after the curly braces is optional. For a specific example, the following lineairy {-bl -pt=0 -bt=0 -sbt=0}could be placed in a .perltidyrc file, and then invoked at will withperltidy -airy somefile.pl
(Either CW-airy or CW--airy may be used). - Skipping leading non-perl commands with -x or --look-for-hash-bang
- If your script has leading lines of system commands or other text which are not valid perl code, and which are separated from the start of the perl code by a hash-bang line, ( a line of the form CW#!...perl ), you must use the -x flag to tell perltidy not to parse and format any lines before the hash-bang line. This option also invokes perl with a -x flag when checking the syntax. This option was originally added to allow perltidy to parse interactive VMS scripts, but it should be used for any script which is normally invoked with CWperl -x.
- Making a file unreadable
-
The goal of perltidy is to improve the readability of files, but there
are two commands which have the opposite effect, --mangle and
--extrude. They are actually
merely aliases for combinations of other parameters. Both of these
strip all possible whitespace, but leave comments and pod documents,
so that they are essentially reversible. The
difference between these is that --mangle puts the fewest possible
line breaks in a script while --extrude puts the maximum possible.
Note that these options do not provided any meaningful obfuscation, because
perltidy can be used to reformat the files. They were originally
developed to help test the tokenization logic of perltidy, but they
have other uses.
One use for --mangle is the following:
perltidy --mangle myfile.pl -st | perltidy -o myfile.pl.new
This will form the maximum possible number of one-line blocks (see next section), and can sometimes help clean up a badly formatted script. A similar technique can be used with --extrude instead of --mangle to make the minimum number of one-line blocks. Another use for --mangle is to combine it with -dac to reduce the file size of a perl script. - One-line blocks
-
There are a few points to note regarding one-line blocks. A one-line
block is something like this,
if ($x > 0) { $y = 1 / $x }where the contents within the curly braces is short enough to fit on a single line. With few exceptions, perltidy retains existing one-line blocks, if it is possible within the line-length constraint, but it does not attempt to form new ones. In other words, perltidy will try to follow the one-line block style of the input file. If an existing one-line block is longer than the maximum line length, however, it will be broken into multiple lines. When this happens, perltidy checks for and adds any optional terminating semicolon (unless the -nasc option is used) if the block is a code block. The main exception is that perltidy will attempt to form new one-line blocks following the keywords CWmap, CWeval, and CWsort, because these code blocks are often small and most clearly displayed in a single line. One-line block rules can conflict with the cuddled-else option. When the cuddled-else option is used, perltidy retains existing one-line blocks, even if they do not obey cuddled-else formatting. Occasionally, when one-line blocks get broken because they exceed the available line length, the formatting will violate the requested brace style. If this happens, reformatting the script a second time should correct the problem. - Debugging
- The following flags are available for debugging: --dump-defaults or -ddf will write the default option set to standard output and quit --dump-profile or -dpro will write the name of the current configuration file and its contents to standard output and quit. --dump-options or -dop will write current option set to standard output and quit. --dump-long-names or -dln will write all command line long names (passed to Get_options) to standard output and quit. --dump-short-names or -dsn will write all command line short names to standard output and quit. --dump-token-types or -dtt will write a list of all token types to standard output and quit. --dump-want-left-space or -dwls will write the hash CW%want_left_space to standard output and quit. See the section on controlling whitespace around tokens. --dump-want-right-space or -dwrs will write the hash CW%want_right_space to standard output and quit. See the section on controlling whitespace around tokens. -DEBUG will write a file with extension .DEBUG for each input file showing the tokenization of all lines of code.
- Working with MakeMaker, AutoLoader and SelfLoader
- The first CW$VERSION line of a file which might be eval'd by MakeMaker is passed through unchanged except for indentation. Use --nopass-version-line, or -npvl, to deactivate this feature. If the AutoLoader module is used, perltidy will continue formatting code after seeing an __END__ line. Use --nolook-for-autoloader, or -nlal, to deactivate this feature. Likewise, if the SelfLoader module is used, perltidy will continue formatting code after seeing a __DATA__ line. Use --nolook-for-selfloader, or -nlsl, to deactivate this feature.
- Working around problems with older version of Perl
- Perltidy contains a number of rules which help avoid known subtleties and problems with older versions of perl, and these rules always take priority over whatever formatting flags have been set. For example, perltidy will usually avoid starting a new line with a bareword, because this might cause problems if CWuse strict is active. There is no way to override these rules.
HTML OPTIONS
- The -html master switch
-
The flag -html causes perltidy to write an html file with extension
.html. So, for example, the following command
perltidy -html somefile.pl
will produce a syntax-colored html file named somefile.pl.html which may be viewed with a browser. Please Note: In this case, perltidy does not do any formatting to the input file, and it does not write a formatted file with extension .tdy. This means that two perltidy runs are required to create a fully reformatted, html copy of a script. - The -pre flag for code snippets
- When the -pre flag is given, only the pre-formatted section, within the <PRE> and </PRE> tags, will be output. This simplifies inclusion of the output in other files. The default is to output a complete web page.
- The -nnn flag for line numbering
- When the -nnn flag is given, the output lines will be numbered.
- The -toc, or --html-table-of-contents flag
- By default, a table of contents to packages and subroutines will be written at the start of html output. Use -ntoc to prevent this. This might be useful, for example, for a pod document which contains a number of unrelated code snippets. This flag only influences the code table of contents; it has no effect on any table of contents produced by pod2html (see next item).
- The -pod, or --pod2html flag
-
There are two options for formatting pod documentation. The default is
to pass the pod through the Pod::Html module (which forms the basis of
the pod2html utility). Any code sections are formatted by perltidy, and
the results then merged. Note: perltidy creates a temporary file when
Pod::Html is used; see FILES. Also, Pod::Html creates temporary
files for its cache.
NOTE: Perltidy counts the number of CW=cut lines, and either moves the
pod text to the top of the html file if there is one CW=cut, or leaves
the pod text in its original order (interleaved with code) otherwise.
Most of the flags accepted by pod2html may be included in the perltidy
command line, and they will be passed to pod2html. In some cases,
the flags have a prefix CWpod to emphasize that they are for the
pod2html, and this prefix will be removed before they are passed to
pod2html. The flags which have the additional CWpod prefix are:
--[no]podheader --[no]podindex --[no]podrecurse --[no]podquiet --[no]podverbose --podflush
The flags which are unchanged from their use in pod2html are:--backlink=s --cachedir=s --htmlroot=s --libpods=s --title=s --podpath=s --podroot=s
where 's' is an appropriate character string. Not all of these flags are available in older versions of Pod::Html. See your Pod::Html documentation for more information. The alternative, indicated with -npod, is not to use Pod::Html, but rather to format pod text in italics (or whatever the stylesheet indicates), without special html markup. This is useful, for example, if pod is being used as an alternative way to write comments. - The -frm, or --frames flag
-
By default, a single html output file is produced. This can be changed
with the -frm option, which creates a frame holding a table of
contents in the left panel and the source code in the right side. This
simplifies code browsing. Assume, for example, that the input file is
MyModule.pm. Then, for default file extension choices, these three
files will be created:
MyModule.pm.html - the frame MyModule.pm.toc.html - the table of contents MyModule.pm.src.html - the formatted source code
Obviously this file naming scheme requires that output be directed to a real file (as opposed to, say, standard output). If this is not the case, or if the file extension is unknown, the -frm option will be ignored. - The -text=s, or --html-toc-extension flag
- Use this flag to specify the extra file extension of the table of contents file when html frames are used. The default is toc. See Specifying File Extensions.
- The -sext=s, or --html-src-extension flag
- Use this flag to specify the extra file extension of the content file when html frames are used. The default is src. See Specifying File Extensions.
- The -hent, or --html-entities flag
- This flag controls the use of Html::Entities for html formatting. By default, the module Html::Entities is used to encode special symbols. This may not be the right thing for some browser/language combinations. Use --nohtml-entities or -nhent to prevent this.
- Style Sheets
-
Style sheets make it very convenient to control and adjust the
appearance of html pages. The default behavior is to write a page of
html with an embedded style sheet.
An alternative to an embedded style sheet is to create a page with a
link to an external style sheet. This is indicated with the
-css=filename, where the external style sheet is filename. The
external style sheet filename will be created if and only if it does
not exist. This option is useful for controlling multiple pages from a
single style sheet.
To cause perltidy to write a style sheet to standard output and exit,
use the -ss, or --stylesheet, flag. This is useful if the style
sheet could not be written for some reason, such as if the -pre flag
was used. Thus, for example,
perltidy -html -ss >mystyle.css
will write a style sheet with the default properties to file mystyle.css. The use of style sheets is encouraged, but a web page without a style sheets can be created with the flag -nss. Use this option if you must to be sure that older browsers (roughly speaking, versions prior to 4.0 of Netscape Navigator and Internet Explorer) can display the syntax-coloring of the html files. - Controlling HTML properties
-
Note: It is usually more convenient to accept the default properties
and then edit the stylesheet which is produced. However, this section
shows how to control the properties with flags to perltidy.
Syntax colors may be changed from their default values by flags of the either
the long form, -html-color-xxxxxx=n, or more conveniently the short form,
-hcx=n, where xxxxxx is one of the following words, and x is the
corresponding abbreviation:
Token Type xxxxxx x ---------- -------- -- comment comment c number numeric n identifier identifier i bareword, function bareword w keyword keyword k quite, pattern quote q here doc text here-doc-text h here doc target here-doc-target hh punctuation punctuation pu parentheses paren p structural braces structure s semicolon semicolon sc colon colon co comma comma cm label label j sub definition name subroutine m pod text pod-text pdA default set of colors has been defined, but they may be changed by providing values to any of the following parameters, where n is either a 6 digit hex RGB color value or an ascii name for a color, such as 'red'. To illustrate, the following command will produce an html file somefile.pl.html with aqua keywords:perltidy -html -hck=00ffff somefile.pl
and this should be equivalent for most browsers:perltidy -html -hck=aqua somefile.pl
Perltidy merely writes any non-hex names that it sees in the html file. The following 16 color names are defined in the HTML 3.2 standard:black => 000000, silver => c0c0c0, gray => 808080, white => ffffff, maroon => 800000, red => ff0000, purple => 800080, fuchsia => ff00ff, green => 008000, lime => 00ff00, olive => 808000, yellow => ffff00 navy => 000080, blue => 0000ff, teal => 008080, aqua => 00ffff,Many more names are supported in specific browsers, but it is safest to use the hex codes for other colors. Helpful color tables can be located with an internet search for HTML color tables. Besides color, two other character attributes may be set: bold, and italics. To set a token type to use bold, use the flag -html-bold-xxxxxx or -hbx, where xxxxxx or x are the long or short names from the above table. Conversely, to set a token type to NOT use bold, use -nohtml-bold-xxxxxx or -nhbx. Likewise, to set a token type to use an italic font, use the flag -html-italic-xxxxxx or -hix, where again xxxxxx or x are the long or short names from the above table. And to set a token type to NOT use italics, use -nohtml-italic-xxxxxx or -nhix. For example, to use bold braces and lime color, non-bold, italics keywords the following command would be used:perltidy -html -hbs -hck=00FF00 -nhbk -hik somefile.pl
The background color can be specified with -html-color-background=n, or -hcbg=n for short, where n is a 6 character hex RGB value. The default color of text is the value given to punctuation, which is black as a default. Here are some notes and hints: 1. If you find a preferred set of these parameters, you may want to create a .perltidyrc file containing them. See the perltidy man page for an explanation. 2. Rather than specifying values for these parameters, it is probably easier to accept the defaults and then edit a style sheet. The style sheet contains comments which should make this easy. 3. The syntax-colored html files can be very large, so it may be best to split large files into smaller pieces to improve download times.
SOME COMMON INPUT CONVENTIONS
Specifying Block Types
Several parameters which refer to code block types may be customized by also specifying an associated list of block types. The type of a block is the name of the keyword which introduces that block, such as if, else, or sub. An exception is a labeled block, which has no keyword, and should be specified with just a colon.
For example, the following parameter specifies CWsub, labels, CWBEGIN, and CWEND blocks:
-cscl="sub : BEGIN END"
(the meaning of the -cscl parameter is described above.) Note that quotes are required around the list of block types because of the spaces.
Specifying File Extensions
Several parameters allow default file extensions to be overridden. For example, a backup file extension may be specified with -bext=ext, where ext is some new extension. In order to provides the user some flexibility, the following convention is used in all cases to decide if a leading '.' should be used. If the extension CWext begins with CWA-Z, CWa-z, or CW0-9, then it will be appended to the filename with an intermediate '.' (or perhaps an '_' on VMS systems). Otherwise, it will be appended directly.
For example, suppose the file is somefile.pl. For CW-bext=old, a '.' is added to give somefile.pl.old. For CW-bext=.old, no additional '.' is added, so again the backup file is somefile.pl.old. For CW-bext=~, then no dot is added, and the backup file will be somefile.pl~ .
SWITCHES WHICH MAY BE NEGATED
The following list shows all short parameter names which allow a prefix 'n' to produce the negated form:
D anl asc aws b bbb bbc bbs bli boc bok bol bot syn ce csc
dac dbc dcsc dnl dws dp dpro dsm dsc ddf dln dop dsn dtt dwls dwrs
f fll frm hsc html ibc icb icp iob isbc lp log lal x lsl ple pod bl
sbl okw ola oll ple pvl q opt sbc sfs ssc sts se st sob
t tac tbc toc tp tsc tqw w
Equivalently, the prefix 'no' or 'no-' on the corresponding long names may be used.
LIMITATIONS
- Parsing Limitations
- Perltidy should work properly on most perl scripts. It does a lot of self-checking, but still, it is possible that an error could be introduced and go undetected. Therefore, it is essential to make careful backups and to test reformatted scripts. The main current limitation is that perltidy does not scan modules included with 'use' statements. This makes it necessary to guess the context of any bare words introduced by such modules. Perltidy has good guessing algorithms, but they are not infallible. When it must guess, it leaves a message in the log file. If you encounter a bug, please report it.
- What perltidy does not parse and format
- Perltidy indents but does not reformat comments and CWqw quotes. Perltidy does not in any way modify the contents of here documents or quoted text, even if they contain source code. (You could, however, reformat them separately). Perltidy does not format 'format' sections in any way. And, of course, it does not modify pod documents.
FILES
- Temporary files
- Under the -html option with the default --pod2html flag, a temporary file is required to pass text to Pod::Html. Unix systems will try to use the POSIX tmpnam() function. Otherwise the file perltidy.TMP will be temporarily created in the current working directory.
- Special files when standard input is used
- When standard input is used, the log file, if saved, is perltidy.LOG, and any errors are written to perltidy.ERR unless the -se flag is set. These are saved in the current working directory.
- Files overwritten
- The following file extensions are used by perltidy, and files with these extensions may be overwritten or deleted: .ERR, .LOG, .TEE, and/or .tdy, .html, and .bak, depending on the run type and settings.
- Files extensions limitations
- Perltidy does not operate on files for which the run could produce a file with a duplicated file extension. These extensions include .LOG, .ERR, .TEE, and perhaps .tdy and .bak, depending on the run type. The purpose of this rule is to prevent generating confusing filenames such as somefile.tdy.tdy.tdy.
SEE ALSO
perlstyle(1), Perl::Tidy(3)
VERSION
This man page documents perltidy version 20031021.
CREDITS
Michael Cartmell supplied code for adaptation to VMS and helped with v-strings.
Yves Orton supplied code for adaptation to the various versions of Windows.
Axel Rose supplied a patch for MacPerl.
Hugh S. Myers designed and implemented the initial Perl::Tidy module interface.
Many others have supplied key ideas, suggestions, and bug reports; see the CHANGES file.
AUTHOR
Steve Hancock email: perltidy at users.sourceforge.net http://perltidy.sourceforge.net
COPYRIGHT
Copyright (c) 2000-2003 by Steve Hancock
LICENSE
This package is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License.
Please refer to the file COPYING for details.
DISCLAIMER
This package is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.