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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
commit | 8ffec2a3aba6f114784e11f89ef1d57a096ae540 (patch) | |
tree | ccebcbad06203e8241a8e7249f8e6c478a3682ea /man/env.x | |
parent | Initial commit. (diff) | |
download | coreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.tar.xz coreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.zip |
Adding upstream version 8.32.upstream/8.32upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/env.x')
-rw-r--r-- | man/env.x | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/man/env.x b/man/env.x new file mode 100644 index 0000000..29d173c --- /dev/null +++ b/man/env.x @@ -0,0 +1,67 @@ +'\" Copyright (C) 1998-2020 Free Software Foundation, Inc. +'\" +'\" This is free software. You may redistribute copies of it under the terms +'\" of the GNU General Public License <https://www.gnu.org/licenses/gpl.html>. +'\" There is NO WARRANTY, to the extent permitted by law. +[NAME] +env \- run a program in a modified environment +[DESCRIPTION] +.\" Add any additional description here +[OPTIONS] +.SS "\-S/\-\-split\-string usage in scripts" +The +.B \-S +option allows specifying multiple parameters in a script. +Running a script named +.B 1.pl +containing the following first line: +.PP +.RS +.nf +#!/usr/bin/env \-S perl \-w \-T +\&... +.fi +.RE +.PP +Will execute +.B "perl \-w \-T 1.pl". +.PP +Without the +.B '\-S' +parameter the script will likely fail with: +.PP +.RS +.nf +/usr/bin/env: 'perl \-w \-T': No such file or directory +.fi +.RE +.PP +See the full documentation for more details. +.PP +.SS "\-\-default-signal[=SIG]" usage +This option allows setting a signal handler to its default +action, which is not possible using the traditional shell +trap command. The following example ensures that seq +will be terminated by SIGPIPE no matter how this signal +is being handled in the process invoking the command. + +.PP +.RS +.nf +sh \-c 'env \-\-default-signal=PIPE seq inf | head \-n1' +.fi +.RE +.PP + +[NOTES] +POSIX's exec(2) pages says: +.RS +"many existing applications wrongly assume that they start with certain +signals set to the default action and/or unblocked.... Therefore, it is best +not to block or ignore signals across execs without explicit reason to do so, +and especially not to block signals across execs of arbitrary (not closely +cooperating) programs." +.RE + +[SEE ALSO] +sigaction(2), sigprocmask(2), signal(7) |