From: Lennart Poettering Date: Mon, 11 Aug 2014 17:28:53 +0000 (+0200) Subject: man: improve documentation for StandardOutput= and StandardInput= X-Git-Tag: v216~203 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=79c1afc67f973eaece8f1b7016e016bb33c256a7 man: improve documentation for StandardOutput= and StandardInput= --- diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index a1eb1127d..cfcf996da 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -365,39 +365,47 @@ , , or - . If - is selected, - standard input will be connected to + . + + If is + selected, standard input will be + connected to /dev/null, i.e. all read attempts by the process - will result in immediate EOF. If - is selected, - standard input is connected to a TTY - (as configured by + will result in immediate EOF. + + If is + selected, standard input is connected + to a TTY (as configured by TTYPath=, see below) and the executed process becomes the controlling process of the terminal. If the terminal is already - being controlled by another process, the - executed process waits until the current - controlling process releases the - terminal. - - is similar to , - but the executed process is forcefully - and immediately made the controlling + being controlled by another process, + the executed process waits until the + current controlling process releases + the terminal. + + is similar + to , but the + executed process is forcefully and + immediately made the controlling process of the terminal, potentially removing previous controlling processes from the - terminal. is + terminal. + + is similar to but if the terminal already has a controlling process start-up of the executed - process fails. The - option is only - valid in socket-activated services, - and only when the socket configuration - file (see + process fails. + + The + option is only valid in + socket-activated services, and only + when the socket configuration file + (see systemd.socket5 for details) specifies a single socket only. If this option is set, standard @@ -407,7 +415,9 @@ with daemons designed for use with the traditional inetd8 - daemon. This setting defaults to + daemon. + + This setting defaults to . @@ -418,56 +428,84 @@ of , , , + , , , - , + , , - , - or - . If set to - , the file - descriptor of standard input is - duplicated for standard output. If set - to , standard - output will be connected to + or + . + + + duplicates the file descriptor of + standard input for standard + output. + + connects + standard output to /dev/null, i.e. everything written to it will be - lost. If set to , - standard output will be connected to a - tty (as configured via + lost. + + connects + standard output to a tty (as + configured via TTYPath=, see below). If the TTY is used for output only, the executed process will not become the controlling process of the terminal, and will not fail or wait for other processes to release the - terminal. - connects standard output to the - syslog3 - system syslog - service. - connects it with the kernel log buffer - which is accessible via - dmesg1. - connects it with the journal which is - accessible via - journalctl1 - (Note that everything that is written - to syslog or kmsg is implicitly stored - in the journal as well, those options - are hence supersets of this - one). , - and - work - similarly but copy the output to the - system console as - well. connects - standard output to a socket from - socket activation, semantics are - similar to the respective option of - StandardInput=. - This setting defaults to the value set - with + terminal. + + + connects standard output with the + journal which is accessible via + journalctl1. + Note that everything that is written + to syslog or kmsg (see below) is + implicitly stored in the journal as + well, the specific two options listed + below are hence supersets of this + one. + + connects + standard output to the syslog3 + system syslog service, in addition to + the journal. Note that the journal + daemon is usually configured to + forward everything it receives to + syslog anyway, in which case this + option is no different from + . + + connects + standard output with the kernel log + buffer which is accessible via + dmesg1, + in addition to the journal. The + journal daemon might be configured to + send all logs to kmsg anyway, in which + case this option is no different from + . + + , + and + work in + a similar way as the three options + above but copy the output to the + system console as well. + + connects + standard output to a socket acquired + via socket activation. The semantics + are similar to the same option of + StandardInput=. + + This setting defaults to the + value set with in systemd-system.conf5,