grep — removing text after delimiter token

Question

I have a file in which I need to eliminate everything after the first ; on every line.

So a file like this:

sdfsdsdf;
fsdfsddf;sdfsd;

Will result in this:

sdfsdsdf
fsdfsddf

I have looked into grep and sed. I would appreciate an answer incorporating either of these commands.

Answer 1

sed is probably easiest and faster than awk or perl in this circumstance:

sed 's/^\([^;][^;]*\);.*$/\1/' some_file_name

Answer 2

another option is to use the cut command

cat a.file | cut -d';' -f1

Answer 3

I typically use awk for things like this:

cat a.file | awk -F=";" '{ print $1 }'

That will take each line of a file and print the first group before the delimiter -F

Answer 4

Here's a way to do it using GNU grep:

grep -Po "^[^;]+(?=;?)" filename