file display
$cat filename show file
$cat file1 file2 connection shows file1 and file2 $head -1 filename shows the first line of the file
$tail -5 filename displays the fifth last line of the file $diff file1 file2 displays the difference between file1 and file2
$sort filename sorts the lines in the file and displays
$sort -f filename sort, regardless of case
$sort -u filename sort and remove duplicate lines
$uniq filename displays the non-repeated lines in the file filename (lines with the same content, but not adjacent to each other, do not count as duplicates)
$wc filename counts characters, words, and lines in a file
$wc -l filename count the number of lines in the file