s6-frontend
Software
skarnet.org

The s6-frontend-alias-chpst program

s6-frontend-alias-chpst implements runit's chpst command by rewriting itself into a command line made of idiomatic chainloading s6 commands.

Interface

     s6-frontend-alias-chpst [ -v ] [ -P ] [ -0 ] [ -1 ] [ -2 ] [ -u user ] [ -U user ] [ -b argv0 ] [ -e dir ] [ -/ root ] [ -n niceness ] [ -l|-L lock ] [ -m bytes ] [ -d bytes ] [ -o n ] [ -p n ] [ -f bytes ] [ -c bytes ] prog...

When s6-frontend has been configured with the --enable-aliases-runit option, the s6-frontend-alias-chpst program is built, and at installation time, a chpst symbolic link is created, pointing to it.

s6-frontend-alias-chpst implements most of the functionality of chpst, as closely as possible. It does so by rewriting itself into a command line that may invoke one or more of the following programs:

• The Unix nice command
• The s6 s6-setsid command
• The s6 s6-envdir command
• The s6 s6-setlock command
• The s6 s6-applyuidgid command
• The s6 s6-envuidgid command
• The s6 s6-softlimit command
• The execline fdclose command
• The execline exec command
• The non-standard (but ubiquitous) Unix chroot command

Notes

• When the -v option is given, s6-frontend-alias-chpst prints an informational message to stderr, showing the entire command line it is going to execute into.
• s6-frontend-alias-chpst is a convenience program, written so that runit users can keep using chpst while learning the corresponding idiomatic s6 commands. However, it is not an "official" interface. chpst acts as a big toolbox, whereas s6 prefers the "one function = one tool" philosophy. It is recommended that runit users who are new to s6 use the -v option to see how their chpst invocation translates into s6 parlance.
• Some chpst -u invocations do not translate perfectly because s6 uses a slightly different model of acquiring user and group identity via s6-envuidgid. This should not prevent chpst from working.