Linux伊甸园论坛 » Shell编程 » 【讨论】tr [A-Z] [a-z] 不 work (都是 wildcard 惹的祸)

dearvoid 发表于 2006-12-28 17:39

【讨论】tr [A-Z] [a-z] 不 work (都是 wildcard 惹的祸)

今下午帮一同事解决了一个 script 中的小问题, 在这里情景再现一下, 大家看看怎么回事 :)
[font=Courier][quote]
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[4226 0] #[/color] echo Hello World | tr [A-Z] [a-z]
aello aorld
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[4226 0] #[/color] o
[/quote][/font]

[[i] 本帖最后由 dearvoid 于 2007-10-16 21:32 编辑 [/i]]

li-jiahuan 发表于 2006-12-28 23:24

老大那是什么啊
怎么错得还跟你的不一样

[code]
[0 No.2018 huan@huan ~/tmp]$ echo Hello World | tr [A-Z] [a-z]
tr: 额外的操作数 ‘k’
请尝试执行‘tr --help’来获取更多信息。

[1 No.2019 huan@huan ~/tmp]$ echo Hello World | tr '[A-Z]' '[a-z]'
hello world

[0 No.2020 huan@huan ~/tmp]$ echo Hello World | tr 'A-Z' 'a-z'
hello world

[0 No.2021 huan@huan ~/tmp]$ echo $BASH_VERSION
3.1.17(1)-release

[0 No.2022 huan@huan ~/tmp]$
[/code]

dearvoid 发表于 2006-12-29 08:48

[QUOTE=li-jiahuan]老大那是什么啊
怎么错得还跟你的不一样
[/QUOTE]
这下更有意思了, 大家继续 :)

li-jiahuan 发表于 2006-12-29 09:48

鬼啊。。。
2楼是在家里发的
现在这个是在公司里
同样的ubuntu edgy
同样的bash_version

[php]
[0 No.517 huanlf@huanlf-desktop ~]$ echo Hello World | tr [A-Z] [a-z]
hello world

[0 No.518 huanlf@huanlf-desktop ~]$ echo $BASH_VERSION
3.1.17(1)-release

[0 No.519 huanlf@huanlf-desktop ~]$
[/php]

dearvoid 发表于 2006-12-29 09:54

[QUOTE=li-jiahuan]鬼啊。。。
2楼是在家里发的
现在这个是在公司里
同样的ubuntu edgy
同样的bash_version
[/QUOTE]
这就是问题的神奇之所在 :)

dearvoid 发表于 2006-12-29 14:36

谜底揭晓:[font=Courier][quote]
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[14859 0][/color] [color=red]; mkdir foo
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[14859 0][/color] [color=red]; cd ./foo
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; echo Hello World | tr [A-Z] [a-z]
[/color]hello world
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; touch a
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; echo Hello World | tr [A-Z] [a-z]
[/color]aello aorld
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; touch k
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; echo Hello World | tr [A-Z] [a-z]
[/color]tr: extra operand `k'
Try `tr --help' for more information.
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 1][/color] [color=red]; o
[/color][/quote][/font]

[[i] 本帖最后由 dearvoid 于 2007-10-16 21:33 编辑 [/i]]

abby_h12345 发表于 2006-12-29 23:20

还是避免让bash解释参数，加上引号

li-jiahuan 发表于 2006-12-30 11:56

嗯
记得abs里说过要引号

附
[php]
prayaya@Prayaya:~$ echo HeLLo WoRLd | perl -pe ' tr /[A-Z]/[a-z]/ '
hello world

prayaya@Prayaya:~$ echo HeLLo WoRLd | perl -pe ' y/[A-Z]/[a-z]/ '
hello world

prayaya@Prayaya:~$ echo HeLLo WoRLd | perl -pe ' s/([A-Z])/\L$1/g '
hello world

prayaya@Prayaya:~$
[/php]

li-jiahuan 发表于 2006-12-30 13:13

看到老大改标题了
想起一个很常用的应用
用于判断是否有符合一定模式的文件存在

[php]
prayaya@Prayaya:~/test$ rm * -rf
prayaya@Prayaya:~/test$ [ abc = ab* ] && echo Yes || echo No
No
prayaya@Prayaya:~/test$ touch abc
prayaya@Prayaya:~/test$ [ abc = ab* ] && echo Yes || echo No
Yes
[/php]

但实际上我自己不用这种不太好理解的方式
我更喜欢 ls ab* &>/dev/null  && echo Yes || echo No

zhuomingliang 发表于 2006-12-30 13:20

没有理解touch 的问题，解释一下？

li-jiahuan 发表于 2006-12-30 13:27

亮兄看帖不专心：）
是不是有MM在边上啊

已经解释说了是‘用于判断是否有符合一定模式的文件存在’
dearvoid还专门改了下标题
‘都是 wildcard 惹的祸’

这么示例一下好让更多人理解
请结合9楼的代码看

[php]
prayaya@Prayaya:~/test$ rm * -rf
prayaya@Prayaya:~/test$ echo *
*
prayaya@Prayaya:~/test$ touch abc
prayaya@Prayaya:~/test$ echo *
abc
prayaya@Prayaya:~/test$ echo ab*
abc
prayaya@Prayaya:~/test$

[/php]

dearvoid 发表于 2006-12-30 14:00

[QUOTE=li-jiahuan]看到老大改标题了
想起一个很常用的应用
用于判断是否有符合一定模式的文件存在
[php]
prayaya@Prayaya:~/test$ rm * -rf
prayaya@Prayaya:~/test$ [ abc = ab* ] && echo Yes || echo No
No
prayaya@Prayaya:~/test$ touch abc
prayaya@Prayaya:~/test$ [ abc = ab* ] && echo Yes || echo No
Yes
[/php]
[/QUOTE]
不是很明白这个用法, 如果还有一个文件叫 abcd 该怎么办呢?
[font=Courier][quote]
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 0][/color] [color=red]; rm -rf *
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 0][/color] [color=red]; [ abc = ab* ] && echo yes
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 1][/color] [color=red]; touch abc
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 0][/color] [color=red]; [ abc = ab* ] && echo yes
[/color]yes
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 0][/color] [color=red]; touch abcd
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 0][/color] [color=red]; [ abc = ab* ] && echo yes
[/color]bash: [: too many arguments
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[18357 2][/color] [color=red]; o
[/color][/quote][/font]

[[i] 本帖最后由 dearvoid 于 2007-10-16 21:34 编辑 [/i]]

li-jiahuan 发表于 2006-12-30 14:45

证明了我说的是实话
我不常用这方法所以也就记不住。。。

完整的代码应该是这样的吧
[php]
prayaya@Prayaya:~/kk$ [ "$(echo ab*)" != "ab*" ] && echo Yes || echo No
No
prayaya@Prayaya:~/kk$ touch abc
prayaya@Prayaya:~/kk$ [ "$(echo ab*)" != "ab*" ] && echo Yes || echo No
Yes
prayaya@Prayaya:~/kk$ touch abcd
prayaya@Prayaya:~/kk$ [ "$(echo ab*)" != "ab*" ] && echo Yes || echo No
Yes
prayaya@Prayaya:~/kk$
[/php]
希望不会再错了。。。

dearvoid 发表于 2006-12-30 14:54

不好用 :( forget it

zhuomingliang 发表于 2006-12-30 18:39

[QUOTE]
[color=#0000ff] [14859 0][/color] [color=red]; touch a
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[14859 0][/color] [color=red]; echo Hello World | tr [A-Z] [a-z]
[/color]aello aorld
[/QUOTE] 脑子短路了，没有理解是怎么传递的:(

dearvoid 发表于 2006-12-31 09:23

[font=Courier][quote]
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[24898 0][/color] [color=red]; mkdir foo
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp)-
[24898 0][/color] [color=red]; cd ./foo
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; echo [a-z]
[/color][a-z]
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; touch a
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; echo [a-z]
[/color]a
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; touch k
[/color][color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; echo [a-z]
[/color]a k
[color=blue]-(dearvoid@LinuxEden:tty3)-(~/tmp/foo)-
[24898 0][/color] [color=red]; o
[/color][/quote][/font]

[[i] 本帖最后由 dearvoid 于 2007-10-16 21:35 编辑 [/i]]

zhuomingliang 发表于 2006-12-31 22:17

忘记回帖了，半夜脑袋果然清晰，昨天睡觉的时候想通了。:w

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