| 1 | #!/usr/bin/env bash | 
| 2 | # | 
| 3 | # Pattern for testing if a function has succeeded or failed with set -e: | 
| 4 | # | 
| 5 | #    SUMMARY: Call it through $0. | 
| 6 | # | 
| 7 | # Useful for test frameworks! | 
| 8 | # | 
| 9 | # Usage: | 
| 10 | #   demo/dollar0-errexit.sh <function name> | 
| 11 |  | 
| 12 | set -o nounset | 
| 13 | set -o pipefail | 
| 14 | set -o errexit | 
| 15 |  | 
| 16 | # Should produce TWO lines, not THREE. | 
| 17 | # And the whole thing FAILS with exit code 1. | 
| 18 | myfunc() { | 
| 19 | echo one | 
| 20 | echo two | 
| 21 | false      # should FAIL here | 
| 22 | echo three | 
| 23 | } | 
| 24 |  | 
| 25 | mypipeline() { myfunc | wc -l; } | 
| 26 |  | 
| 27 | # Prints three lines because errexit is implicitly disabled. | 
| 28 | # It also shouldn't succeed. | 
| 29 | bad() { | 
| 30 | if myfunc | wc -l; then | 
| 31 | echo true | 
| 32 | else | 
| 33 | echo false | 
| 34 | fi | 
| 35 | echo status=$? | 
| 36 | } | 
| 37 |  | 
| 38 | # This fixes the behavior.  Prints two lines and fails. | 
| 39 | good() { | 
| 40 | if $0 mypipeline; then | 
| 41 | echo true | 
| 42 | else | 
| 43 | echo false | 
| 44 | fi | 
| 45 | echo status=$? | 
| 46 | } | 
| 47 |  | 
| 48 | # This is pretty much what 'bad' is dong. | 
| 49 | not-a-fix() { | 
| 50 | set +o errexit | 
| 51 | mypipeline | 
| 52 | local status=$? | 
| 53 | set -o errexit | 
| 54 |  | 
| 55 | if test $? -eq 0; then | 
| 56 | echo true | 
| 57 | else | 
| 58 | echo false | 
| 59 | fi | 
| 60 | echo status=$? | 
| 61 | } | 
| 62 |  | 
| 63 | "$@" |