grep 精确匹配某一字符串

比如使用 ps 想 grep 出 top。 desktop 因为含有 top 也被匹配出来。

[root@localhost ~]# ps -aux | grep top
root     21211  0.0  1.0 1100696 19752 ?       Sl   Dec05   0:00 nautilus --no-default-window --force-desktop
root     26243  0.0  0.0 143496  1560 pts/5    T    15:34   0:00 top
root     26245  0.0  0.0    452     4 pts/5    R+   15:34   0:00 grep --color=auto top

使用 grep -w 即可

-w, --word-regexp
              Select only those lines containing matches that form whole words.  The test is that the matching substring must either be at the beginning of the line,  or  preceded  by  a
              non-word  constituent  character.   Similarly,  it  must  be either at the end of the line or followed by a non-word constituent character.  Word-constituent characters are
              letters, digits, and the underscore.

[root@localhost ~]# ps -aux | grep -w top
root     26243  0.0  0.0 143496  1560 pts/5    T    15:34   0:00 top
root     26291  0.0  0.0 112644   976 pts/5    R+   15:37   0:00 grep --color=auto -w top