bash-hackers-wiki/docs/syntax/ccmd/while_loop.md

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