Shell Programming and Scripting

#!/usr/bin/env bash

# @(#) s1       Demonstrate source function from variable.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
em() { pe "$*" >&2 ; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C

pl " Remove variable v1 and function x1:"
unset v1
unset -f x1
set | grep v1
set | grep x1

pl " Create variable:"
v1="
x1() { printf ' Hello, world from x1.\n' ; }
"

pl " Variable v1 = $v1"

pl " Results, try to execute x1, expect failure:"
x1

pl " Source, then execute x1"
source <( printf "%s" "$v1")
x1

exit 0

$ ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 3.16.0-4-amd64, x86_64
Distribution        : Debian 8.7 (jessie) 
bash GNU bash 4.3.30

-----
 Remove variable v1 and function x1:
_i=' Remove variable v1 and function x1:'
_i=' Remove variable v1 and function x1:'

-----
 Create variable:

-----
 Variable v1 = 
x1() { printf ' Hello, world from x1.\n' ; }


-----
 Results, try to execute x1, expect failure:
./s1: line 29: x1: command not found

-----
 Source, then execute x1
 Hello, world from x1.