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33 lines
1.2 KiB
Plaintext
33 lines
1.2 KiB
Plaintext
====== The while-loop ======
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===== Synopsis =====
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<code>
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while <LIST1> ; do
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<LIST2>
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done
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</code>
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===== Description =====
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The while-loop is relatively simple in what it does: it executes the [[syntax:basicgrammar#lists | command list]] ''<LIST1>'' and if the exit code of it was 0 (TRUE) it executes ''<LIST2>''. This happens again and again until ''<LIST1>'' returns FALSE.
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This is exactly the opposite of the [[syntax:ccmd:until_loop | until loop]].
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:!: Like all loops (both ''for''-loops, ''while'' and ''until''), this loop can be
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* terminated (broken) by the ''break'' command, optionally as ''break N'' to break ''N'' levels of nested loops
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* forced to immediately do the next iteration using the ''continue'' 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>'', 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: [[syntax:ccmd:until_loop | The until loop]]
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* Internal: [[commands:builtin:read#code_examples|code examples of the read builtin command]] to see how you can loop over lines
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