awk command to change date format

Question

I have a file that contains the below records:

**cat Date.txt** SEPT,30-SEP-2017 MARCH,30-MAR-2018 JULY,30-JUL-2017 DECEM,30-DEC-2017 AUGS,30-AUG-2017

I want the output to be:

 SEPT,20170930 MARCH,20180330 JULY,20170730 DECEM,20171230 AUGS,20170830

I have done a script with a while loop, as given below.

 cat Date.txt > /tmp/exp.part while read line do Dat=$(echo $line | awk -F , '{print $1}') DatNew=$(date -d $Exp +%Y%m%d) echo $DatNew done < /tmp/exp.part

I want to know if I can do it from the awk command, instead of writing a while loop.

Guru · Accepted Answer · 2017-07-28 04:24:32Z

One way using system command within awk: Input file:

$ cat file 27-SEP-2017 28-MAR-2018 27-JUL-2017 27-DEC-2017 29-AUG-2017 $ awk '{system("date -d " $0 " +%Y%m%d")}' file 20170927 20180328 20170727 20171227 20170829

For the updated input file:

$ cat file SEP,27-SEP-2017 MAR,28-MAR-2018 JUL,27-JUL-2017 DEC,27-DEC-2017 AUG,29-AUG-2017 $ awk -F, '{system("date -d " $2 " +%Y%m%d")}' file 20170927 20180328 20170727 20171227 20170829

For the updated requirement:

$ cat file SEPT,30-SEP-2017 MARCH,30-MAR-2018 JULY,30-JUL-2017 DECEM,30-DEC-2017 AUGS,30-AUG-2017 $ awk -F, '{cmd="date -d "q $2 q" "s"+%Y%m%d"s; cmd|getline x;print $1,x}' dq='"' sq="'" OFS=, file SEPT,20170930 MARCH,20180330 JULY,20170730 DECEM,20171230 AUGS,20170830

$ cat file SEP,27-SEP-2017 MAR,28-MAR-2018 JUL,27-JUL-2017 DEC,27-DEC-2017 AUG,29-AUG-2017 $ awk '{system("date -d " $0 " +%Y%m%d")}' file date: invalid date SEP,27-SEP-2017' date: invalid date MAR,28-MAR-2018' date: invalid date JUL,27-JUL-2017' date: invalid date DEC,27-DEC-2017' date: invalid date `AUG,29-AUG-2017'
Can you format your content better? I am not able to make out whether the whole content is in the same line or different lines?
Perfect, but I want the first column as well. Which will be like: SEP,20170927

alan · Accepted Answer · 2022-04-15 23:05:52Z

Following on Guru's answer, this also seemed to work:

$ awk -F, '{cmd="date -d "$2" +%Y%m%d"; cmd|getline x;print $1,x}' OFS=',' file SEPT,20170930 MARCH,20180330 JULY,20170730 DECEM,20171230 AUGS,20170830

Note the awk version was actually mawk:

$ awk -W version mawk 1.3.3 Nov 1996, Copyright (C) Michael D. Brennan

Collectives™ on Stack Overflow

awk command to change date format

2 Answers 2

7 Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Related