tldr/pages/common/if.md

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# if
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> Simple shell conditional.
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- Echo a different thing depending on a command's success:
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`{{command}} && echo "success" || echo "failure"`
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- Full if syntax:
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`if {{condition}}; then echo "true"; else echo "false"; fi`
- List available if conditions:
`help test`
- Test if a given variable is empty:
`if [[ -z $GIT_BRANCH ]]; then echo "true"; else echo "false"; fi`
- Test if a file exists:
`if [[ -e {{filename}} ]]; then echo "true"; else echo "false"; fi`
- If directory not exists:
`if [[ ! -d {{path/to/directory}} ]]; then echo "true"; else echo "false"; fi`