env1

Usage

Overview

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

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

-a, --argv0=ARG

pass ARG as the zeroth argument of COMMAND

-i, --ignore-environment

start with an empty environment

--env0-from=FILE

read NUL-delimited environment entries from FILE

-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 signal(s) to do nothing

--list-signal-handling

list non default signal handling to standard error

-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. An empty SIG argument is a no-op.

Script option handling

The -S option allows specifying multiple arguments 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.

Notes

POSIX's exec(3p) pages says: