Tr

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tr (translate)12

功能作用(Function)

转化、压缩和/或删除标准输入中的字符, 将其写入标准输出。

Translate, squeeze, and/or delete characters from standard input, writing to standard output.

语法(Synopsis)

1
tr [OPTION]... SET1 [SET2]

选项(Option)

  • -c, -C, --complement: 使用SET1的补集(use the complement of SET1)
  • -d, --delete: 删除SET1中的字符, 不转化(delete characters in SET1, do not translate)
  • -s, --squeeze-repeats: 将最后指定的SET中列出的重复字符的每个序列替换为该字符的单次出现(replace each sequence of a repeated character that is listed in the last specified SET, with a single occurrence of that character)
  • -t, --truncate-set1: 截断SET1到SET2的长度(first truncate SET1 to length of SET2)

描述(Description)

SET通常为字符串。其中转义字符3有:

  • \NNN: 三位八进制数值(character with octal value NNN (1 to 3 octal digits))
  • \\: 反斜线(backslash)
  • \a: 响铃符(audible BEL)4
  • \b: 退格符(backspace)
  • \f: 换页符(form feed)
  • \n: 换行符(new line)
  • \r: 回车符(return)
  • \t: 水平制表符(horizontal tab)
  • \v: 垂直制表符(vertical tab)

SET可以由以下部分组成:

  • CHAR1-CHAR2: 从CHAR1到CHAR2的所有字符按升序排列
  • [CHAR*]: 在SET2中, SET1的长度个CHAR副本
  • [CHAR*REPEAT]: REPEAT个CHAR副本, 如果REPEAT以0开始, 则为八进制数
  • [:alnum:]: 所有字母和数字
  • [:alpha:]: 所有字母
  • [:blank:]: 所有水平空白
  • [:cntrl:]: 所有控制字符5
  • [:digit:]: 所有数字
  • [:graph:]: 所有可打印字符, 不包括空格
  • [:lower:]: 所有小写字母
  • [:print:]: 所有可打印字符, 包括空格
  • [:punct:]: 所有标点符号
  • [:space:]: 所有水平或垂直空白
  • [:upper:]: 所有大写字母
  • [:xdigit:]: 所有十六进制数字
  • [=CHAR=]: 所有等价于CHAR的字符

如果没有给出-d且SET1和SET2都出现, 则进行转化(translation)。-t只能在转化时时使用。

当SET2的长度小于SET1的长度, 以SET2的最后一个字符对SET2进行扩展并扩展到与SET1长度相同。

当SET2的长度大于SET1的长度, SET2中多余的字符将被忽略。

只有[:lower:]和[:upper:]保证按升序展开;在含有SET2的转化中, 它们只能成对使用来进行大小写转换。-s使用最后一个指定的SET, 并用于转化(translation)或删除(deletion)。

示例(Example)

小写转大写

1
echo "hello\t10023 world 456" | tr "a-z" "A-Z"
1
HELLO	10023 WORLD 456

"a-z", "A-Z", 都是SET, 分别表示所有的小写字母和所有的大写字母。

制表符转空格

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echo "hello\t10023 world 456" | tr "\t" " "
1
hello 10023 world 456

删除数字

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echo "hello\t10023 world 456" | tr -d "0-9"
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hello	 world

只保留数字

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echo "hello\t10023 world 456" | tr -cd "0-9"
1
10023456

压缩字符9和p

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echo "hello\t199923 world app 456" | tr -s "9p"
1
hello	1923 world ap 456

截断SET1

1
echo "abcd" | tr -t "abcd" "123"
1
123d
1
echo "abcd" | tr "abcd" "123"
1
1233

man tr

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TR(1)                            User Commands                           TR(1)



NAME
    tr - translate or delete characters

SYNOPSIS
    tr [OPTION]... SET1 [SET2]

DESCRIPTION
    Translate, squeeze, and/or delete characters from standard input, writ-
    ing to standard output.

    -c, -C, --complement
           use the complement of SET1
     
    -d, --delete
           delete characters in SET1, do not translate
     
    -s, --squeeze-repeats
           replace each sequence of a repeated character that is listed  in
           the last specified SET, with a single occurrence of that charac-
           ter
     
    -t, --truncate-set1
           first truncate SET1 to length of SET2
     
    --help display this help and exit
     
    --version
           output version information and exit
     
    SETs are specified as strings  of  characters.   Most  represent  them-
    selves.  Interpreted sequences are:
     
    \NNN   character with octal value NNN (1 to 3 octal digits)
     
    \\     backslash
     
    \a     audible BEL
     
    \b     backspace
     
    \f     form feed
     
    \n     new line
     
    \r     return
     
    \t     horizontal tab
     
    \v     vertical tab
     
    CHAR1-CHAR2
           all characters from CHAR1 to CHAR2 in ascending order
     
    [CHAR*]
           in SET2, copies of CHAR until length of SET1
     
    [CHAR*REPEAT]
           REPEAT copies of CHAR, REPEAT octal if starting with 0
     
    [:alnum:]
           all letters and digits
     
    [:alpha:]
           all letters
     
    [:blank:]
           all horizontal whitespace
     
    [:cntrl:]
           all control characters
     
    [:digit:]
           all digits
     
    [:graph:]
           all printable characters, not including space
     
    [:lower:]
           all lower case letters
     
    [:print:]
           all printable characters, including space
     
    [:punct:]
           all punctuation characters
     
    [:space:]
           all horizontal or vertical whitespace
     
    [:upper:]
           all upper case letters
     
    [:xdigit:]
           all hexadecimal digits
     
    [=CHAR=]
           all characters which are equivalent to CHAR
     
    Translation  occurs  if  -d is not given and both SET1 and SET2 appear.
    -t may be used only when translating.  SET2 is extended  to  length  of
    SET1  by  repeating its last character as necessary.  Excess characters
    of SET2 are ignored.  Only [:lower:] and [:upper:]  are  guaranteed  to
    expand  in  ascending  order;  used in SET2 while translating, they may
    only be used in pairs to specify case conversion.   -s  uses  the  last
    specified SET, and occurs after translation or deletion.

AUTHOR
    Written by Jim Meyering.

REPORTING BUGS
    GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
    Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT
    Copyright  (C) 2019 Free Software Foundation, Inc.  License GPLv3+: GNU
    GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
    This is free software: you are free  to  change  and  redistribute  it.
    There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
    Full documentation <https://www.gnu.org/software/coreutils/tr>
    or available locally via: info '(coreutils) tr invocation'



GNU coreutils 8.31                March 2019                             TR(1)

Reference

1. “tr命令_Linux tr 命令用法详解：将字符进行替换压缩和删除.” [Online]. Available: https://man.linuxde.net/tr. [Accessed: 12-Feb-2020] ↩
2. “Tr (Unix),” 维基百科, 自由的百科全书. 21-Dec-2019 [Online]. Available: https://zh.wikipedia.org/w/index.php?title=Tr_(Unix)&oldid=57354145. [Accessed: 12-Feb-2020] ↩
3. “转义字符_百度百科.” [Online]. Available: https://baike.baidu.com/item/%E8%BD%AC%E4%B9%89%E5%AD%97%E7%AC%A6/86397?fromtitle=%E8%BD%AC%E4%B9%89%E7%AC%A6&fromid=6151115. [Accessed: 12-Feb-2020] ↩
4. “Bell character,” Wikipedia. 14-Sep-2019 [Online]. Available: https://en.wikipedia.org/w/index.php?title=Bell_character&oldid=915701003. [Accessed: 12-Feb-2020] ↩
5. “控制字符,” 维基百科，自由的百科全书. 31-Jan-2018 [Online]. Available: https://zh.wikipedia.org/w/index.php?title=%E6%8E%A7%E5%88%B6%E5%AD%97%E7%AC%A6&oldid=48096464. [Accessed: 12-Feb-2020] ↩