Text Processing
Manipulating text files can be a time-consuming process if done manually. The commands in Table A.5 are commonly used to manipulate the contents of text files. These commands normally work by outputting the data to standard out (otherwise known as the screen), so to capture these changes, you normally redirect the output to another text file using the greater-than sign (>). For example:
sort /etc/passwd > /tmp/users.txt
Table A.5. Commands Commonly Used to Process Text Files | COMMAND | GENERAL USAGE | DESCRIPTION |
|---|
| expand | expand FILE | Converts tab characters to spaces in the specified file. | | joe | joe FILE | Text-editing utility. | | nl | nl FILE | Assigns line numbers and displays the specified file. | | pr | pr [OPTIONS] FILE | Formats a text file for printing. | | sort | sort FILE | Alphabetically sorts and displays the specified file. | | unexpand | unexpand FILE | Converts spaces to tab characters in the specified file. | | uniq | uniq FILE | Displays all unique lines in the specified file. | | vi | vi FILE | Text-editing utility. Use vimtutor for an introduction to this utility. | | wc | wc [OPTIONS] FILE | Returns the number of lines, words, and characters in the specified file. |
|