Shell Programming and Scripting

This might or might not work for the OP. This code doesn't remove the last field, it changes it to an empty string. The distinction is important because the OFS will appear at the end of the line separating the next to the last field from the now empty last field.

If you use Yoda's approach, the last field and the last field separator will both be removed. Note, however, that Yoda's approach will also fail on some systems (including at least Mac OS X) if you're trying to remove the only field from a line. A standards conforming awk script trying to remove the last field from each line (possibly producing an empty line) would require something like:

Code:

awk 'BEGIN{FS=OFS=","}{--NF <= 0 ? $0 = "" : $1 = $1;print}'

which when given the input:

Code:

1,2,3
1,2
1
a,b,c

produces the output:

Code:

1,2
1

a,b

while Yoda's script ('{ NF--; $1 = $1 }') produces:

Code:

1,2
1
1
a,b

on some systems (again, including Mac OS X).

None working for me either.... I tried on SunOS (on windows) and Darwin on (Mac OS)...

Use nawk in SunOS.

Code:

nawk -F, '{ NF--; $1 = $1 }1' OFS=, file

Or Don's proposal:

Code:

nawk 'BEGIN{FS=OFS=","}{--NF <= 0 ? $0 = "" : $1 = $1;print}' file

Here's a perl. This will work.

Code:

[user@host ~]$ cat file
1,2,3,4,5,6,7,8
1,2,3,4,5,6,7,8
1,2,3,4,5,6,7,8
1,2,3,4,5,6,7,8
[user@host ~]$ perl -F',' -lane 'print join (",", @F[0..$#F-1])' file
1,2,3,4,5,6,7
1,2,3,4,5,6,7
1,2,3,4,5,6,7
1,2,3,4,5,6,7
[user@host ~]$