Character processing command
1, Sort order: sort
sort [options] filename
Options:
-f: ignore case
-n: numeric be sorted (sort default string)
-r: reverse sequencing
-t: Specifies the separator (default delimiter is a tab)
-kn [, m]: sorted according to fields specified range. Starting from n fields, m end of the field. (Default to the end of the line)
sort -n -t ":" -k 3,3 / etc / passwd are sorted in the third field. (Where -n is specified in the numerical order, or will be shown in the case 2 after 11 and 12)
2, statistics command: wc
wc [options] filename
Options:
-l: only count the number of rows
-w: only count the number of words
-m: only count the number of characters