正则表达式

grep '\<root\>' /etc/paswd
cut -d: -f1 /etc/passwd
cut -d: -c1-3 /etc/passwd
grep '\<root\>' /etc/passwd | cut -d: -f1
cut -d: -f1 /etc/passwd | grep '\<root\>'
tail -f /var/log
cat
grep aaaa
sort -t: +2 -n /etc/passwd
sort -t: +2 -r /etc/passwd
du | sort -n -r | head -n -3
du | sort -n -r | head -n -3 | cut -f2
wc /etc/passwd
wc -l -w -c /etc/passwd
uniq
diff
patch -p0 < patch.2.6.9
^ . * $
a\{18\}
/usr/share/dict/words
grep '.\{40,\}' /usr/share/dict/words
i18n
grep '^i.\{18\}n$' /usr/share/dict/words
grep -v '^#' /etc/squid/squid.conf | grep -v '^$'|wc -l
vi
%s/word/world/g
%s/\/word/world/g