awk?

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31 events

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Dec 16, 2024 at 18:35	comment	added	Stéphane Chazelas		@jrw32982 I do mention it already here: also found in perl since perl 4; one of the earliest tools to support it (and `\x{ffff...}` before C added `\uFFFF` I believe which I mention as well).
Dec 16, 2024 at 18:06	comment	added	jrw32982		Stéphane and I have had this conversation before, but `"\x27"` is also valid in `perl`, which is where I use it for this kind of thing: `BEGIN { $q = "\x27" }`
Dec 9, 2024 at 8:46	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 42 characters in body
Dec 9, 2024 at 8:23	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 136 characters in body
Dec 9, 2024 at 7:30	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 149 characters in body
Dec 9, 2024 at 7:08	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 220 characters in body
Dec 9, 2024 at 6:55	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 220 characters in body
Dec 9, 2024 at 6:39	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 67 characters in body
Dec 8, 2024 at 20:43	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 323 characters in body
Dec 8, 2024 at 15:15	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 139 characters in body
Dec 8, 2024 at 14:14	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 126 characters in body
Dec 8, 2024 at 11:24	vote	accept	Ed Morton
Dec 8, 2024 at 8:36	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 4 characters in body
Dec 7, 2024 at 22:29	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 422 characters in body
Dec 7, 2024 at 21:14	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 66 characters in body
Dec 7, 2024 at 20:36	comment	added	Ed Morton		You're right, I got it backwards (been doing that all day and correcting!). Thanks for confirming.
Dec 7, 2024 at 20:02	comment	added	Stéphane Chazelas		@EdMorton, that's the other way round `\x27` is not defined for anything other than `$'...'`, `\47` for C, awk, printf format (both of which are shaped after C), and `\047` for `echo` and `printf`'s `%b`.
Dec 7, 2024 at 19:10	comment	added	Ed Morton		So.... after doing some wading through POSIX and reading your answer, am I right in thinking that `\027` and `\27` are both undefined behavior per POSIX for all 3 of grep, sed and awk and that `\x47` is defined by POSIX for awk but undefined for grep and sed? I added the standards references to the bottom of my question, if you know of anywhere else in POSIX that those escape sequences are defined for those tools, please let me know.
Dec 7, 2024 at 18:14	comment	added	Ed Morton		Regarding `awk_code=$(here doc); awk "$awk_code"` - I think that's the first time I've seen awk code stored in a variable where it was a useful thing to do. Until now I've thought it was just to help syntax highlighting of shell scripts in some editors.
Dec 7, 2024 at 18:03	comment	added	Ed Morton		Then I'd have to do `printf '%q'` or something to go the other way. Copy/paste is simpler and `\047` works in both contexts.
Dec 7, 2024 at 18:01	comment	added	Stéphane Chazelas		@EdMorton, you can always replace `awk` with `printf '%s\n' > file.awk` to store that awk code, same as you'd do for `sh`, `sed` code or anything else.
Dec 7, 2024 at 18:00	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 108 characters in body
Dec 7, 2024 at 17:59	comment	added	Ed Morton		I'm not sure what you mean. I'll fairly often start writing a script (actually a utility awk function) as `awk 'BEGIN{print "It\047s not pretty"}'` and then as it grows decide I should move it to a file `foo.awk` containing `BEGIN{print "It\047s not pretty"}` to execute as `awk -f foo.awk` or vice-versa. If my starting point was instead `awk 'BEGIN{print "It'\''s not pretty"}'` then I couldn't save `BEGIN{print "It'\''s not pretty"}` to a file `foo.awk` and execute it as `awk -f foo.awk`.
Dec 7, 2024 at 17:21	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 646 characters in body
Dec 7, 2024 at 15:59	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 5 characters in body
Dec 7, 2024 at 15:50	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 5 characters in body
Dec 7, 2024 at 15:48	comment	added	Stéphane Chazelas		@EdMorton, in what sort of context would that be an actual problem? It's the same in `sh -c 'echo "It'\''s not pretty, but it works"'` vs having `echo "It's not pretty, but it works"` in a shell script.
Dec 7, 2024 at 15:44	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 191 characters in body
Dec 7, 2024 at 15:41	comment	added	Ed Morton		Thanks for the answer, I'll read it in detail a little later but regarding "In any case for ' specifically, there's no need to specify the point code, as $'\'' works." - I use `\047` in my scripts so they will work whether I use them from the command line as `awk 'foo \047 bar'` or stored in a file as `awk -f scriptfile` and you can't do that if you write the script as `foo '\'' bar` instead.
Dec 7, 2024 at 15:36	history	edited	Stéphane Chazelas	CC BY-SA 4.0	added 191 characters in body
Dec 7, 2024 at 15:30	history	answered	Stéphane Chazelas	CC BY-SA 4.0

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