NAME

     setproctitle — set process title

LIBRARY

     library “libbsd”

SYNOPSIS

     #include <sys/types.h>
     #include <bsd/unistd.h>

     void
     setproctitle_init(int argc, char *argv[], char *envp[]);

     void
     setproctitle(const char *fmt, ...);

DESCRIPTION

     The setproctitle() library routine sets the process title that appears on the ps(1) command.

     The setproctitle_init() library routine only needs to be called (before any call to
     setproctitle() and with main() arguments), if the automatic constructor support has not been
     linked in through the libbsd-ctor pkg-config file.

     The title is set from the executable's name, followed by the result of a printf(3) style
     expansion of the arguments as specified by the fmt argument.  If the fmt argument begins
     with a “-” character, the executable's name is skipped.

     If fmt is NULL, the process title is restored.

EXAMPLES

     To set the title on a daemon to indicate its activity:

           setproctitle("talking to %s", inet_ntoa(addr));

SEE ALSO

     ps(1), w(1), kvm(3), kvm_getargv(3), printf(3)

STANDARDS

     The setproctitle() function is implicitly non-standard.  Other methods of causing the ps(1)
     command line to change, including copying over the argv[0] string are also implicitly non-
     portable.  It is preferable to use an operating system supplied setproctitle() if present.

     Unfortunately, it is possible that there are other calling conventions to other versions of
     setproctitle(), although none have been found by the author as yet.  This is believed to be
     the predominant convention.

     It is thought that the implementation is compatible with other systems, including NetBSD and
     BSD/OS.

HISTORY

     The setproctitle() function first appeared in FreeBSD 2.2.  Other operating systems have
     similar functions.

     The setproctitle_init() function is a libbsd extension not present on the BSDs, avoid using
     it in portable code.

AUTHORS

     Peter Wemm <peter@FreeBSD.org> stole the idea from the Sendmail 8.7.3 source code by Eric
     Allman <eric@sendmail.org>.

BUGS

     Never pass a string with user-supplied data as a format without using ‘%s’.  An attacker can
     put format specifiers in the string to mangle your stack, leading to a possible security
     hole.  This holds true even if the string was built using a function like snprintf(), as the
     resulting string may still contain user-supplied conversion specifiers for later
     interpolation by setproctitle().

     Always use the proper secure idiom:

           setproctitle("%s", string);