Basic Text Display and Filtering

Command	Description
head file	Show first 10 lines
tail file	Show last 10 lines
nl file	Show file with line numbers
cat file	Display entire file
cut -d':' -f1 file	Extract columns (fields)
grep word file	Search for matching lines
sort file	Sort lines alphabetically
uniq file	Remove duplicate lines
wc file	Count lines, words, and characters

Example:

grep error /var/log/syslog

Shows all lines containing the word “error”.

wc data.txt

Output example:

10  50  250 data.txt

(lines, words, characters)