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# AWK

From ArchWiki

AWK is a small programming language designed for text processing. Its name is derived from the surnames of its authors: Alfred Aho, Peter Weinberger, and Brian Kernighan. The language is standardized and widely available on Unix-like systems.

## Installation

On Arch, the awk(1p) command is provided by gawk, which is installed by default, with native Unicode support and a load of extra features.

Note gawk is designed to be able to gain additional language features at runtime by dynamically loading the so-called extensions -- extensions that were bundled within the software distribution are out-of-box to use, but the separately maintained gawkextlibAUR-* plugins do require manual installation.

### Alternative implementations

Like many other core utilities, there are several more-or-less compliant implementations available:

- BusyBox — The BusyBox implementation is not that well performant but has a smaller footprint suitable for memory strained environment.

  https://git.busybox.net/busybox/tree/editors/awk.c || busybox

- GoAWK — AWK implementation in Go language.

  https://github.com/benhoyt/goawk || goawkAUR

- nawk — The "new" AWK as described in The AWK Programming Language, a.k.a. BWK AWK or the One-True-AWK, is now co-maintained by Arnold Robbins and B. W. Kernighan, featuring UTF-8 and csv support.

  https://awk.dev/ || nawk

- mawk — A rather performant AWK implementation.

  https://invisible-island.net/mawk/ || mawkAUR

## Troubleshooting

### Assignment to `ARGC` variable via `-v` option does not preserve in runtime

Although undocumented, it appears that many implementations will reset the `ARGC` variable internally after processing the variable assignment of `-v` options specified on command line. Therefore, to get desired value of `ARGC` variable in runtime (e.g. `BEGIN` code blocks), it's required to set the variable in code block directly:

    BEGIN {
      ARGC=1;
      ...
    }

Note An upcoming update to POSIX has documented this issue specifically.

## See also

- nawk(1): a refcard-style man page of nawk
- The GNU AWK manual: both a comprehensive tutorial and a canonical reference text on gawk(1)
- Alpine Linux's community wiki article on AWK: has some notes on implementation difference between BusyBox and other AWKs
- AWK tech notes: language gotchas and design difference compared to other modern programming languages
- Idiomatic AWK: how concise an AWK program could be

Categories:

- Programming languages
- Commands

AWK
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