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   env    ( 1 )

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Имя (Name)

env - run a program in a modified environment

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Синопсис (Synopsis)

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

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Описание (Description)

Set each NAME to VALUE in the environment and run COMMAND.

Mandatory arguments to long options are mandatory for short options too.

-i, --ignore-environment start with an empty environment

-0, --null end each output line with NUL, not newline

-u, --unset=NAME remove variable from the environment

-C, --chdir=DIR change working directory to DIR

-S, --split-string=S process and split S into separate arguments; used to pass multiple arguments on shebang lines

--block-signal[=SIG] block delivery of SIG signal(s) to COMMAND

--default-signal[=SIG] reset handling of SIG signal(s) to the default

--ignore-signal[=SIG] set handling of SIG signals(s) to do nothing

--list-signal-handling list non default signal handling to stderr

-v, --debug print verbose information for each processing step

--help display this help and exit

--version output version information and exit

A mere - implies -i. If no COMMAND, print the resulting environment.

SIG may be a signal name like 'PIPE', or a signal number like '13'. Without SIG, all known signals are included. Multiple signals can be comma-separated.

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Параметры (Options)

-S/--split-string usage in scripts
       The -S option allows specifying multiple parameters in a script.
       Running a script named 1.pl containing the following first line:

              #!/usr/bin/env -S perl -w -T
              ...

       Will execute perl -w -T 1.pl .

       Without the '-S' parameter the script will likely fail with:

              /usr/bin/env: 'perl -w -T': No such file or directory

       See the full documentation for more details.

   --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.

              sh -c 'env --default-signal=PIPE seq inf | head -n1'

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Примечание (Note)

POSIX's exec(2) pages says: "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."

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