SETPROCTITLE(3)        FreeBSD Library Functions Manual        SETPROCTITLE(3)

NAME
     setproctitle setproctitle_fast - set process title

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

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

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

DESCRIPTION
     The setproctitle() library routine sets the process title that appears on
     the ps(1) command.  The setproctitle_fast() variant is optimized for high
     frequency updates, but may make the ps(1) command slightly slower by not
     updating the kernel cache of the program arguments.

     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), setprogname(3), 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.  The
     setproctitle_fast() function first appeared in FreeBSD 12.  Other
     operating systems have similar functions.

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);

FreeBSD 13.1-RELEASE-p6        November 13, 2020       FreeBSD 13.1-RELEASE-p6