s6
Software
skarnet.org

The s6-fdholder-list program

s6-fdholder-list lists the descriptors currently held by a fd-holding daemon.

Interface

     s6-fdholder-list [ -t timeout ] path

• s6-fdholder-list connects to a s6-fdholderd server process listening on path.
• It gets the list of identifiers corresponding to the currently held file descriptors. It prints that list to stdout, one per line.

Options

• -t timeout : if the operation cannot be processed in timeout milliseconds, then fail with an error message. Communications with the server should be near-instant, so this option is only here to protect users against programming errors (connecting to the wrong socket, for instance).

Exit codes

• 0: success.
• 1: the server denied the operation. The meaning of the error messages is explained here.
• 100: wrong usage.
• 111: system call failed - that includes attempting to connect to a nonexistent socket, or one where no s6-fdholderd daemon is listening.