> I was surprised that "Awk '!a[$0]++'" works too (on Mac at least). If I "ls Awk" in \usr\bin, it says Awk is there. If I "ls awk" it says awk is also there—but it seems they're the same file, and it's only pretending Awk is a file. AWK also... I never noticed that before!
I presume this is a side-effect of the macOS default filesystem being case-insensitive. I'm running macOS with a case-sensitive fs and that does not work:
$ awk
usage: awk [-F fs] [-v var=value] [-f progfile | 'prog'] [file ...]
$ Awk
-bash: Awk: command not found
This explains how "-i inplace" works: https://www.gnu.org/software/gawk/manual/html_node/Extension...
Also, this version[1], which works with gawks from 2013 and after, changes the file in place as it goes, where the original version just makes the array which then needs to be printed/saved:
(The original version seems to only work with files up to about 2GB.)p.s. The current misspelled title using "Awk", raises another question–I was surprised that "Awk '!a[$0]++'" works too (on Mac at least). If I "ls Awk" in \usr\bin, it says Awk is there. If I "ls awk" it says awk is also there—but it seems they're the same file, and it's only pretending Awk is a file. AWK also... I never noticed that before!
[0] I sympathize—I once tried to submit a !!Con talk.
[1] https://unix.stackexchange.com/a/320128