Commit 19f0ae79 authored by Craig Small's avatar Craig Small

documentation: Update watch man page

Added locale details and fixed this manual page to follow standards
including ordering it the right way, keeping the names of things
consistent and removing authors section.
Signed-off-by: Craig Small's avatarCraig Small <csmall@enc.com.au>
parent 1310a768
.TH WATCH "1" "June 2011" "procps-ng" "User Commands"
.TH WATCH 1 "2016-06-03" "procps-ng" "User Commands"
.SH NAME
watch \- execute a program periodically, showing output fullscreen
.SH SYNOPSIS
......@@ -9,11 +9,8 @@ watch \- execute a program periodically, showing output fullscreen
runs
.I command
repeatedly, displaying its output and errors (the first screenfull). This
allows you to watch the program output change over time. By default, the
program is run every 2 seconds.
By default,
.B watch
will run until interrupted.
allows you to watch the program output change over time. By default,
\fIcommand\fR is run every 2 seconds and \fBwatch\fR will run until interrupted.
.SH OPTIONS
.TP
\fB\-d\fR, \fB\-\-differences\fR [\fIpermanent\fR]
......@@ -23,7 +20,8 @@ has changed at least once since first iteration.
.TP
\fB\-n\fR, \fB\-\-interval\fR \fIseconds\fR
Specify update interval. The command will not allow quicker than 0.1 second
interval, in which the smaller values are converted.
interval, in which the smaller values are converted. Both '.' and ',' work
for any locales.
.TP
\fB\-p\fR, \fB\-\-precise\fR
Make
......@@ -69,13 +67,81 @@ Display help text and exit.
.TP
\fB\-v\fR, \fB\-\-version\fR
Display version information and exit.
.SH NOTE
Note that POSIX option processing is used (i.e., option processing stops at
.SH "EXIT STATUS"
.PP
.RS
.PD 0
.TP
.B 0
Success.
.TP
.B 1
Various failures.
.TP
.B 2
Forking the process to watch failed.
.TP
.B 3
Replacing child process stdout with write side pipe failed.
.TP
.B 4
Command execution failed.
.TP
.B 5
Closing child process write pipe failed.
.TP
.B 7
IPC pipe creation failed.
.TP
.B 8
Getting child process return value with
.BR waitpid (2)
failed, or command exited up on error.
.TP
.B other
The watch will propagate command exit status as child exit status.
.SH NOTES
POSIX option processing is used (i.e., option processing stops at
the first non\-option argument). This means that flags after
.I command
don't get interpreted by
.BR watch
itself.
.SH BUGS
Upon terminal resize, the screen will not be correctly repainted until the
next scheduled update. All
.B \-\-differences
highlighting is lost on that update as well.
Non-printing characters are stripped from program output. Use "cat -v" as
part of the command pipeline if you want to see them.
Combining Characters that are supposed to display on the character at the
last column on the screen may display one column early, or they may not
display at all.
Combining Characters never count as different in
.I \-\-differences
mode. Only the base character counts.
Blank lines directly after a line which ends in the last column do not
display.
.I \-\-precise
mode doesn't yet have advanced temporal distortion technology to compensate
for a
.I command
that takes more than
.I interval
seconds to execute.
.B watch
also can get into a state where it rapid-fires as many executions of
.I command
as it can to catch up from a previous executions running longer than
.I interval
(for example,
.B netstat
taking ages on a DNS lookup).
.SH EXAMPLES
.PP
To watch for mail, you might do
......@@ -113,97 +179,3 @@ watch uname \-r
isn't guaranteed to work across reboots, especially in the face of
.B ntpdate
or other bootup time-changing mechanisms)
.SH BUGS
Upon terminal resize, the screen will not be correctly repainted until the
next scheduled update. All
.B \-\-differences
highlighting is lost on that update as well.
.PP
Non-printing characters are stripped from program output. Use "cat -v" as
part of the command pipeline if you want to see them.
.PP
Combining Characters that are supposed to display on the character at the
last column on the screen may display one column early, or they may not
display at all.
.PP
Combining Characters never count as different in
.I \-\-differences
mode. Only the base character counts.
.PP
Blank lines directly after a line which ends in the last column do not
display.
.PP
.I \-\-precise
mode doesn't yet have advanced temporal distortion technology to compensate
for a
.I command
that takes more than
.I interval
seconds to execute.
.B watch
also can get into a state where it rapid-fires as many executions of
.I command
as it can to catch up from a previous executions running longer than
.I interval
(for example,
.B netstat
taking ages on a DNS lookup).
.SH "EXIT STATUS"
.PP
.RS
.PD 0
.TP
.B 0
Success.
.TP
.B 1
Various failures.
.TP
.B 2
Forking the process to watch failed.
.TP
.B 3
Replacing child process stdout with write side pipe failed.
.TP
.B 4
Command execution failed.
.TP
.B 5
Closing child process write pipe failed.
.TP
.B 7
IPC pipe creation failed.
.TP
.B 8
Getting child process return value with
.BR waitpid (2)
failed, or command exited up on error.
.TP
.B other
The watch will propagate command exit status as child exit status.
.SH AUTHORS
The original
.B watch
was written by
.UR rembo@\:unisoft.\:com
Tony Rems
.UE
in 1991, with mods and
corrections by Francois Pinard. It was reworked and new features added by
.UR mkc@\:acm.\:org
Mike Coleman
.UE
in 1999. The beep, exec, and error handling features were added by
.UR morty@\:frakir.\:org
Morty Abzug
.UE
in 2008. On a not so dark and stormy morning in March of 2003,
.UR asd@\:suespammers.\:org
Anthony DeRobertis
.UE
got sick of his watches that should update every minute eventually updating
many seconds after the minute started, and added microsecond precision.
Unicode support was added in 2009 by
.UR procps@\:rrod.\:net
Jarrod Lowe
.UE
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