NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | AUTHOR | REPORTING BUGS | COPYRIGHT | SEE ALSO | COLOPHON

ENV(1)                          User Commands                         ENV(1)

NAME         top

       env - run a program in a modified environment

SYNOPSIS         top

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

DESCRIPTION         top

       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         top

   -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         top

       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         top

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

REPORTING BUGS         top

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

COPYRIGHT         top

       Copyright © 2019 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         top

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

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

COLOPHON         top

       This page is part of the coreutils (basic file, shell and text
       manipulation utilities) project.  Information about the project can
       be found at ⟨http://www.gnu.org/software/coreutils/⟩.  If you have a
       bug report for this manual page, see
       ⟨http://www.gnu.org/software/coreutils/⟩.  This page was obtained
       from the tarball coreutils-8.31.tar.xz fetched from
       ⟨http://www.gnutls.org/download.html⟩ on 2019-05-09.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

GNU coreutils 8.31               March 2019                           ENV(1)

Pages that refer to this page: pmpython(1)environ(7)