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Diffstat (limited to 'examples/functions/whatis')
| -rw-r--r-- | examples/functions/whatis | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/examples/functions/whatis b/examples/functions/whatis new file mode 100644 index 0000000..56c5a58 --- /dev/null +++ b/examples/functions/whatis @@ -0,0 +1,52 @@ +# +# whatis -- and implementation of the 10th Edition Unix sh builtin `whatis' +# command. +# +# usage: whatis arg [...] +# +# For each argument, whatis prints the associated value as a parameter, +# builtin, function, alias, or executable file as appropriate. In each +# case, the value is printed in a form which would yield the same value +# if typed as input to the shell itself. +# + +whatis() +{ + local wusage='usage: whatis arg [arg...]' + local fail=0 + + if [ $# -eq 0 ] ; then + echo "$wusage" + return 1 + fi + + for arg + do + case $(builtin type -type $arg 2>/dev/null) in + "alias") + builtin alias "$arg" + ;; + "function") + builtin type "$arg" | sed 1d + ;; + "builtin") + echo builtin "$arg" + ;; + "file") + builtin type -path "$arg" + ;; + *) + # OK, we could have a variable, or we could have nada + if [ "$(eval echo \${$arg+set})" = "set" ] ; then + # It is a variable, and it is set + echo -n "$arg=" + eval echo '\"'\$$arg'\"' + else + echo whatis: $arg: not found + fail=1 + fi + ;; + esac + done + return $fail +} |