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42 lines
1.1 KiB
Markdown
42 lines
1.1 KiB
Markdown
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# The while-loop
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## Synopsis
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while <LIST1> ; do
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<LIST2>
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done
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## Description
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The while-loop is relatively simple in what it does: it executes the
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[command list](/syntax/basicgrammar#lists) `<LIST1>` and if the exit
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code of it was 0 (TRUE) it executes `<LIST2>`. This happens again and
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again until `<LIST1>` returns FALSE.
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This is exactly the opposite of the [until
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loop](/syntax/ccmd/until_loop).
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:!: Like all loops (both `for`-loops, `while` and `until`), this loop
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can be
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- terminated (broken) by the `break` command, optionally as `break N`
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to break `N` levels of nested loops
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- forced to immediately do the next iteration using the `continue`
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command, optionally as `continue N` analog to `break N`
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### Return status
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The return status is the one of the last command executed in `<LIST2>`,
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or `0` (`TRUE`) if none was executed.
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## Examples
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## Portability considerations
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## See also
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- Internal: [The until loop](/syntax/ccmd/until_loop)
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- Internal: [code examples of the read builtin
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command](/commands/builtin/read#code_examples) to see how you can
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loop over lines
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