- 论坛徽章:
- 8
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- [waker@proxy dd3]$ awk 'BEGIN{for(i=0;i<=10000;i++)print i,(i%10)?"":"\n"}' >file
- [waker@proxy dd3]$ time tr -s '\n' <file >/dev/null
- real 0m0.028s
- user 0m0.002s
- sys 0m0.002s
- [waker@proxy dd3]$ time grep -v ^$ file >/dev/null
- real 0m0.270s
- user 0m0.152s
- sys 0m0.009s
- [waker@proxy dd3]$ time grep '.' file >/dev/null
- real 0m1.574s
- user 0m1.508s
- sys 0m0.026s
- [waker@proxy dd3]$ time sed '/^$/d' file >/dev/null
- real 0m0.048s
- user 0m0.042s
- sys 0m0.002s
- [waker@proxy dd3]$ time awk '/./' file >/dev/null
- real 0m0.045s
- user 0m0.039s
- sys 0m0.003s
复制代码
为啥grep总是比较慢,和文件格式有关?
[ 本帖最后由 waker 于 2006-8-18 15:34 编辑 ] |
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