How can I remove all characters in each line after the first space in a text file?

Question

I have a large log file from which I need to extract file names.

The file looks like this:

/path/to/loremIpsumDolor.sit /more/text/here/notAlways/theSame/here
/path/to/anotherFile.ext /more/text/here/differentText/here
.... about 10 million times

I need to extract the file names like this:

loremIpsumDolor.sit
anotherFile.ext

I figure my first strategy is to find/replace all /path/to/ with ''. But I'm stuck how to remove all characters after the space.

Can you help?

Answer 1

sed 's/ .*//' file

It doesn't take any more. The transformed output appears on standard output, of course.

Answer 2

In theory, you could also use awk to grab the filename from each line as:

awk '{ print $1 }' input_file.log

That, of course, assumes that there are no spaces in any of the filenames. awk defaults to looking for whitespace as the field delimiters, so the above snippet would take the first "field" from your log file (your filename) for each line, and output it.