Replace specific characters until pattern

Shell Programming and Scripting
1

Hi experts,

My file looks something like this.

abcXX4,7,234
abc,defg,45XX23,74,123

The number of commas left of the XX can vary. The question is how can I replace all the commas left of the 'XX' with an underscore?

abcXX4,7,234
abc_defg_45XX23,74,123

Thanks!

2

Try:

awk '{gsub(/,/,"_",$1)}1' FS=XX OFS=XX file
2 Likes
3

in bash:

while read a ; do echo ${a//,/_} ; done < file
4

You missed the "until pattern" qualification.

Regards,
Alister

5 
sed -e ':a' -e '/,.*XX/ s/,/_/; ta' file

This is little different (replaces up to the rightmost XX), e.g. in this case

abc,defg,45XX23,1XX1,74,123
6

Hi,
Just for fun, another sed solution but catch first XX occurence:

sed '/[^,]*XX/{;s//\n&/;h;s/\n.*$//;y/,/_/;G;s/\n.*\n//;}' file

Example:

$ echo 'abc,defg,45XX23,1XX1,74,123' | sed '/[^,]*XX/{;s//\n&/;h;s/\n.*$//;y/,/_/;G;s/\n.*\n//;}'
abc_defg_45XX23,1XX1,74,123

Regards.