How to remove first comma on each line in a file

Remove fi开发者_如何转开发rst comma on each line in a file. I presume sed is needed.

sed

sed -i.bak 's/,//' file

awk

awk '{sub(",","")}1' file >temp; mv temp file

shell

while read -r line
do
 echo "${line/,/}"
done <"file" > temp
mv temp file

Yes, sed will do it.

sed s/,// < filename

For first comma:

sed '/,//' < file

If first comma is first character:

sed '/^,//' < file

Yes,

first comma sed '/,//' < file

first character that is a comma sed '/^,//' < file

USEFUL ONE-LINE SCRIPTS FOR SED

sed '/^,//' < file