env

ENV(1)                            User Commands                           ENV(1)



NAME
       env - run a program in a modified environment

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

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.

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'

NOTES
       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."

AUTHOR
       Written by Richard Mlynarik, David MacKenzie, and Assaf Gordon.

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

COPYRIGHT
       Copyright © 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL
       version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There
       is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       sigaction(2), sigprocmask(2), signal(7)

       Full documentation <https://www.gnu.org/software/coreutils/env>
       or available locally via: info '(coreutils) env invocation'



GNU coreutils 8.32                 March 2020                             ENV(1)