Awk in 20 Minutes (2015)

Post by j0057 » Sun, May 03, 2020, 2:47 PM UTC

xorcist wrote: post #74

j_z_reeves wrote: post #46

nice, I finally took the time to read the man pages for awk. And whipped out a script to count the number of errors occurred for a particular day for a postgres log file. cat logfile | awk '/ERROR:/ {counts[$1] = counts[$1] + 1}; END { for (day in counts) print day " : " counts[day]}' | sort I just needed to know how awk programs are structured, the rest is just simple programming! EDIT: I'm not sure if it's actually…

Apart from the useless use of cat, since sort does the work here something like the following would probably suffice: grep ERROR logfile | cut -f 1 -d ' ' | sort | uniq -c

Post by spapas82 » Sun, May 03, 2020, 10:19 PM UTC

jftuga wrote: post #116

One of the things I like to do with mawk.exe under Windows is to automate the same command over a group of files. Let's say the myPgm only takes one file name as a command line parameter, then I can so something like this: dir *.xyz /s/b | mawk "{print 'myPgm -x '$0}" | cmd If the file paths have spaces in them, then you have to wrap the name within double quotes. I have found it challenging to output those in mawk -…

Post by stuuuuuuuuu » Mon, May 04, 2020, 7:08 PM UTC

tekknolagi wrote: post #100

liammonahan wrote: post #32

My absolute favorite example of what's possible with awk is this[0] calculator from Ward Cunningham about splitting expenses on a ski trip. It's a really beautiful little piece of code well-adapted to this problem. [0] - https://c2.com/doc/expense/

This reminds me of a story of a guy who wrote a whole company internal debit system like this (coffee, meals out, etc) and it turned into a currency. I feel like I either saw it here, or a similar forum. Anyone have a link? My searches have not found it...

Post by xorcist » Sat, May 09, 2020, 8:21 AM UTC

j0057 wrote: post #121

xorcist wrote: post #74

Earlier quoted context omitted.

Apart from the useless use of cat, since sort does the work here something like the following would probably suffice: grep ERROR logfile | cut -f 1 -d ' ' | sort | uniq -c

There's really nothing useless about that use of cat: it makes the pipeline compose better from left to right. It's not like you have to pay 25 cents for each process you spawn.