1

In Bash 4.2.25, the set and env output is not escaped, so shell escapes and any non-printable characters won't be copy-pasteable. Take for example this shell session:

$ export foo=$'a\nbar=\baz'
$ env | grep -A 1 foo
foo=a
baraz

Ditto for for example colors - They are printed literally, and can mess up the terminal. How do you print all variables with their values in a way that the output can be copied and pasted to give the same environment?*

* Obviously with the standard caveats about readonly variables, special variables like $_ and the like.

3

You could do:

printvars() (
  eval 'declare() { printf declare; printf " %q" "$@"; echo; }'"
        $(declare -p)"
)

printvars

That could be easily extended to omit read-only variables like:

printvars() (
  eval 'declare() {
          [[ $1 = *r* ]] && return
          printf declare; printf " %q" "$@"; echo
        }'"
        $(declare -p)"
)
  • Redefine declare in a subshell to print its own output. Nice! – l0b0 Apr 16 '13 at 8:59
2
escaped_env() {
    cat /proc/self/environ | while IFS== read -r -d '' name value
    do
        printf '%s=%q\n' "$name" "$value"
    done
}

Example session:

$ export foo=$'a\nbar=\baz'
$ escaped_env | grep foo
foo=$'a\nbar=\baz'

This works, but only for exported variables, and set doesn't seem to have a ␀-separator option.

FYI, the /proc filesystem is not a POSIX.1-2008 feature, and it looks like only Linux implements /proc/self/environ. If your OS doesn't have this file, you may want to use env --null before the pipe.

  • 3
    If your env does not support --null but you're on Linux, you can use cat /proc/self/environ instead. – Stéphane Chazelas Apr 15 '13 at 20:55
  • It looks like /proc/self/environ is not updated when exporting more variables. – l0b0 Apr 16 '13 at 8:37
  • 1
    Hence the use of cat (which in this case is not a UUOC) to pass that updated environment along the execution of a new command. – Stéphane Chazelas Apr 16 '13 at 8:54

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