I am parsing a file and I use awk to get the first and third field.

This is all good; but in the first field I would like to trim the last 4 char from that string; so far I didn't find a way to do this in awk, and the only way to do so, is to make multiple calls so I save the awk output in 2 variables, and then trim the first string.

Is there a more efficient way to do so? This is what the file look like


This is what I run in the loop

echo $output | awk -F, "{print $1, $3}"

This will print the line correctly, but then I want to trim $1, removing the last 4 chars

  • Your code with $1 inside doublequotes " should not work as described; shell needs singlequotes ' to include actual $ in an argument. IF as per your example the unwanted characters always begin with . and . is not used elsewhere, you could treat both as field delimiters: awk -F'[.,]' '{print $1,$4}' – dave_thompson_085 Nov 4 '16 at 7:51

One method is to use awk's substr function. For example, starting with this input:

$ cat input

We can print columns one and three, omitting the last four characters of column one with:

$ awk -F, '{print substr($1, 1, length($1)-4), $3}' input
abcdefghi xyz
riosadsef eis
baifafsag eod
| improve this answer | |
  • Awesome; I felt like there was a better way, instead than write 3 more lines and do the trimming on the variable value. Thanks! – rataplan Nov 4 '16 at 5:48

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