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| bash [2020/08/12 17:19] – [Variables] formatting shawn | bash [2020/08/12 19:07] (current) – [Functions] Adds tips shawn |
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| | ''#!/usr/bin/env bash'' - Use ''bash'' found in the environment path. Protects against not knowing where user's ''bash'' is installed. |
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| ====== set options ====== | ====== set options ====== |
| * ''-e'': causes the script to exit on most command failures (non-zero exit codes) | * ''-e'': causes the script to exit on most command failures (non-zero exit codes) |
| * ''-u'': treats unset variables and parameters other than the special parameters @ or * as an error when performing parameter expansion | * ''-u'': treats unset variables and parameters other than the special parameters @ or * as an error when performing parameter expansion |
| * ''-o'' pipefail: causes the script to exit if a command in a pipeline fails | * ''-o pipefail'': causes the script to exit if a command in a pipeline fails |
| * use a + to unset them if necessary | * use a + to unset them if necessary |
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| * ''$IFS'' - Internal/input field separator (defaults to combo of space, newline and tab) | * ''$IFS'' - Internal/input field separator (defaults to combo of space, newline and tab) |
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| | ====== Functions ====== |
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| | Declaring a function (needs to happen before use): |
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| | ''function <function_name> { ... do things ... }'' |
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| | - or - |
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| | ''<function_name>() { ... do things ... }'' |
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| | * Nothing ever goes inside parentheses. |
| | * Passed parameters can be accessed with ''$1''..''$n''. |
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| | ====== Tips ====== |
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| | * [[https://stackoverflow.com/a/16496491|Use getopts to parse commandline options]]. |
