The cut command performs operations on each line it reads. It is often used for parsing data from log files, csv files, and similar. Given a firewall's log file, for example, cut and sort -u can be used to create a sorted list of unique ip addresses. Add in grep to get a strong tool for carving out data. The following lines show how to extract data from a line of text.

echo '0000 192.168.1.100 192.168.100.1' |cut -d ' ' -f 2
192.168.1.100
echo '0000 192.168.1.100 192.168.100.1' |cut -d ' ' -f 2 |cut -d '.' -f 4
100
echo '0000 192.168.1.100 192.168.100.1' |cut -d ' ' -f 2 |cut -d '.' -f 4|cut -c 1
1

The -d flag sets the delimiter, space in this case, and the -f flag shows which column to return, . The column count starts at .

In the next command, output from the first command is piped to a second command where the delimiter is a period and the column is . Finally, cut is used to extract the first character from the results of the second command.

Review the man page to learn more about using cut.