Linux Text Processing Commands

Linux command-line text processing usually combines small tools through pipelines. The most commonly used tools are:

• cat: print file content.
• grep: filter lines by pattern.
• sed: edit text streams.
• awk: process structured text by fields.
• cut: extract columns from each line.
• sort: sort lines.
• uniq: remove or count adjacent duplicate lines.
• tr: translate or delete characters.

Example pipeline:

cat access.log | grep "ERROR" | awk '{print $1}' | sort | uniq -c

This command filters error lines, extracts the first field, sorts the result, and counts repeated values.

REF

[1]. Shell字符串截取