Most arguments to tsocks are provided in the configuration file (the location of which is defined at configure time by the --with-conf=<file> argument but defaults to /etc/tsocks.conf). The structure of this file is documented in tsocks.conf(8)

Some configuration options can be specified at run time using environment variables as follows:

TSOCKS_CONFFILE

This environment variable overrides the default location of the tsocks configuration file. This variable is not honored if the program tsocks is embedded in is setuid. In addition this environment variable can be compiled out of tsocks with the --disable-envconf argument to configure at build time

TSOCKS_DEBUG

This environment variable sets the level of debug output that should be generated by tsocks (debug output is generated in the form of output to standard error). If this variable is not present by default the logging level is set to 0 which indicates that only error messages should be output. Setting it to higher values will cause tsocks to generate more messages describing what it is doing. If set to -1 tsocks will output absolutely no error or debugging messages. This is only needed if tsocks output interferes with a program it is embedded in. Message output can be permanently compiled out of tsocks by specifying the --disable-debug option to configure at build time

TSOCKS_DEBUG_FILE

This option can be used to redirect the tsocks output (which would normally be sent to standard error) to a file. This variable is not honored if the program tsocks is embedded in is setuid. For programs where tsocks output interferes with normal operation this option is generally better than disabling messages (with TSOCKS_DEBUG = -1)

TSOCKS_USERNAME

This environment variable can be used to specify the username to be used when version 5 SOCKS servers request username/password authentication. This overrides the default username that can be specified in the configuration file using 'default_user', see tsocks.conf(8) for more information. This variable is ignored for version 4 SOCKS servers.

TSOCKS_PASSWORD

This environment variable can be used to specify the password to be used when version 5 SOCKS servers request username/password authentication. This overrides the default password that can be specified in the configuration file using 'default_pass', see tsocks.conf(8) for more information. This variable is ignored for version 4 SOCKS servers.

tsocks will normally not be able to send DNS queries through a SOCKS server since SOCKS V4 works on TCP and DNS normally uses UDP. Version 1.5 and up do however provide a method to force DNS lookups to use TCP, which then makes them proxyable. This option can only enabled at compile time, please consult the INSTALL file for more information.

tsocks will generate error messages and print them to stderr when there are problems with the configuration file or the SOCKS negotiation with the server if the TSOCKS_DEBUG environment variable is not set to -1 or and --disable-debug was not specified at compile time. This output may cause some problems with programs that redirect standard error.

tsocks will not in the above configuration be able to provide SOCKS proxying to setuid applications or applications that are not run from a shell. You can force all applications to LD_PRELOAD the library by placing the path to libtsocks in /etc/ld.so.preload. Please make sure you correctly enter the full path to the library in this file if you do this. If you get it wrong, you will be UNABLE TO DO ANYTHING with the machine and will have to boot it with a rescue disk and remove the file (or try the saveme program, see the INSTALL file for more info). THIS IS A ***WARNING***, please be careful. Also be sure the library is in the root filesystem as all hell will break loose if the directory it is in is not available at boot time.