Shell Programming and Scripting

Don,
If you do not mind to explain why you chose to use a character class to represent the single period instead of escape it.

Code:

sed 's/[.]fr[.].*//' file.txt

It's easier for me to use a single construct in a BRE or ERE that never changes depending on context.

All of the following commands remove the 1st two adjacent periods from each input line processed:

Code:

sed 's/\.\.//'
awk '{sub("\\.\\.","")}1'
awk -v RE='\\\\.\\\\.' '{sub(RE,"")}1'
sed 's/[.][.]//'
awk '{sub("[.][.]","")}1'
awk -v RE='[.][.]' '{sub(RE,"")}1'

Note the varying number of backslashes required when using escapes (one, two , or four for each escaped period), depending on context. But when using the character class expression, the same string works in all three cases.

Don,
Thank you for explaining your thought process, related to it.