I would like to know how i can delete the first column of a csv file with awk or sed
Something like this :
FIRST,SECOND,THIRD To something like that
SECOND,THIRD Thanks in advance
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4 Answers
Following awk will be helping you in same.
awk '{sub(/[^,]*/,"");sub(/,/,"")} 1' Input_file Following sed may also help you in same.
sed 's/\([^,]*\),\(.*\)/\2/' Input_file Explanation:
awk ' ##Starting awk code here. { sub(/[^,]*/,"") ##Using sub for substituting everything till 1st occurence of comma(,) with NULL. sub(/,/,"") ##Using sub for substituting comma with NULL in current line. } 1 ##Mentioning 1 will print edited/non-edited lines here. ' Input_file ##Mentioning Input_file name here. 
5 Comments
anubhava
2
sub calls can be combined into one by sub(/[^,]*,/,"")Xavier Prudent
Why does'nt the command sub(/,/,"") remove all the comma?
RavinderSingh13
Because it's sub its designed to remove only 1 comma, on other hand gsub us for Global substitution which can remove all commas.
dr fu manchu
In my case, with a file with 100000 lines, awk was 8 times faster than sed.
RavinderSingh13
@drfumanchu, thanks for sharing your feedback, good to hear that.
Using awk
$awk -F, -v OFS=, '{$1=$2; $2=$3; NF--;}1' file SECOND,THIRD 
Comments
Using sed : ^[^,]+, regex represent the first column including the first comma. ^ means start of the line, [^,]+, means anything one or more times but a comma sign followed by a comma.
you can use -i with sed to make changes in file if needed.
sed -r 's/^[^,]+,//' input SECOND,THIRD 2 Comments
ctac_
Without the -r option : sed 's/^[^,]*,//' input
Gabriel Hernandez
This one worked for me, sed 's/[^,]*,//'
With Sed
sed -i -r 's@^\w+,@@g' test.csv Grab the begin of the line ^, every character class [A-Za-z0-9] and also underscore until we found comma and replace with nothing. Adding g after delimiters you can do a global substitution.
3 Comments
P....
I doubt if this will give the correct answer.
.* means greedy match so you are going to replace till last comma.
Darby_Crash
Sorry, my bad, i have updated the code.
Fildor
This has been marked as low-quality for length and content. Would you mind elaborating a bit on your suggested command. What are the switches for? ...