env(1) - f39

1ENV(1)                           User Commands                          ENV(1)
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NAME

6       env - run a program in a modified environment
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SYNOPSIS

9       env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]
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DESCRIPTION

12       Set each NAME to VALUE in the environment and run COMMAND.
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14       Mandatory  arguments  to  long  options are mandatory for short options
15       too.
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17       -i, --ignore-environment
18              start with an empty environment
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20       -0, --null
21              end each output line with NUL, not newline
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23       -u, --unset=NAME
24              remove variable from the environment
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26       -C, --chdir=DIR
27              change working directory to DIR
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29       -S, --split-string=S
30              process and split S into separate arguments; used to pass multi‐
31              ple arguments on shebang lines
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33       --block-signal[=SIG]
34              block delivery of SIG signal(s) to COMMAND
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36       --default-signal[=SIG]
37              reset handling of SIG signal(s) to the default
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39       --ignore-signal[=SIG]
40              set handling of SIG signal(s) to do nothing
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42       --list-signal-handling
43              list non default signal handling to stderr
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45       -v, --debug
46              print verbose information for each processing step
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48       --help display this help and exit
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50       --version
51              output version information and exit
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53       A mere - implies -i.  If no COMMAND, print the resulting environment.
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55       SIG  may  be  a  signal name like 'PIPE', or a signal number like '13'.
56       Without SIG, all known signals are included.  Multiple signals  can  be
57       comma-separated.  An empty SIG argument is a no-op.
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59   Exit status:
60       125    if the env command itself fails
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62       126    if COMMAND is found but cannot be invoked
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64       127    if COMMAND cannot be found
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66       -      the exit status of COMMAND otherwise
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OPTIONS

69   -S/--split-string usage in scripts
70       The  -S option allows specifying multiple parameters in a script.  Run‐
71       ning a script named 1.pl containing the following first line:
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73              #!/usr/bin/env -S perl -w -T
74              ...
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76       Will execute perl -w -T 1.pl .
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78       Without the '-S' parameter the script will likely fail with:
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80              /usr/bin/env: 'perl -w -T': No such file or directory
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82       See the full documentation for more details.
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84   --default-signal[=SIG] usage
85       This option allows setting a signal  handler  to  its  default  action,
86       which  is  not  possible using the traditional shell trap command.  The
87       following example ensures that seq will be  terminated  by  SIGPIPE  no
88       matter  how  this  signal  is being handled in the process invoking the
89       command.
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92              sh -c 'env --default-signal=PIPE seq inf | head -n1'
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NOTES

95       POSIX's exec(3p) pages says:
96              "many existing applications wrongly assume that they start  with
97              certain  signals  set to the default action and/or unblocked....
98              Therefore, it is best not to block or ignore signals across  ex‐
99              ecs  without  explicit  reason  to  do so, and especially not to
100              block signals across execs of arbitrary (not  closely  cooperat‐
101              ing) programs."
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AUTHOR

104       Written by Richard Mlynarik, David MacKenzie, and Assaf Gordon.
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REPORTING BUGS

107       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
108       Report any translation bugs to <https://translationproject.org/team/>
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COPYRIGHT

111       Copyright  ©  2023  Free Software Foundation, Inc.  License GPLv3+: GNU
112       GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
113       This is free software: you are free  to  change  and  redistribute  it.
114       There is NO WARRANTY, to the extent permitted by law.
115