4 ms·

Note to all, prepend all your bash script with "set -o errexit -o nounset -o pipefail" It'll save you headaches.

• shawkinaw 12y ago
  Yep, my thought exactly. My standard bash header is #!/bin/bash set -eu IFS=$'\n\t' (Wish there was a shorthand version of pipefail, then I'd always use that too.)
  • LeoPanthera 12y ago
    You can save a line by doing #!/bin/bash -eu
    • krotton 12y ago
      Which is no equivalent if the script is executed using "bash script.sh" ;).
• mod 12y ago
  Can you at least explain what this is doing, outside of saving me headaches?
  • barsonme 12y ago
    set -o errexit (set -e): exit script when command fails set -o nounset (set -u): exit script when it tries to use undeclared variables set -o pipefail: returns error from pipe `|` if any of the commands in the pipe fail (normally just returns an error if the last fails)
  • redsymbol 12y ago
    http://redsymbol.net/articles/unofficial-bash-strict-mode/ http://redsymbol.net/articles/unofficial-bash-strict-mode/
  • Anderkent 12y ago
    -errexit: exit the script when a command fails -nounset: fail when referencing an unset variable -pipefail: fail when the any command in a pipeline fails, not just the last one The last option is unfortunately harder to use, since some programs misbehave in pipelines.
• ArchD 12y ago
  I use the shebang "#!/bin/bash -e". To get the same effect as the "set -o errexit -o nounset", I think you can use "#!/bin/bash -e -u". (There seems to be no option for pipefail.)
  • ploxiln 12y ago
    The "shebang" treats everything after the binary as a single argument. It only does one argument from the shebang and the file itself as the final argument. So it would run that kinda like bash '-e -u' $file But you can do #!/bin/bash -eu
  • yrro 12y ago
    This breaks if your script is sourced by another shell. Best use 'set -eu' at the start instead.