[purpleendurer @ bash ~] tr --help
Usage: tr [OPTION]... SET1 [SET2]
Translate, squeeze, and/or delete characters from standard input,
writing 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 input sequence of a repeated character
                            that is listed in SET1 with a single occurrence
                            of that character
  -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 themselves.
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 SET1 if not
translating nor deleting; else squeezing uses SET2 and occurs after
translation or deletion.

GNU coreutils online help: <http:///software/coreutils/>
Report tr translation bugs to <http:///team/>
For complete documentation, run: info coreutils 'tr invocation'
[purpleendurer @ bash ~]

[purpleenduer @ kylin ~ ] tr --help
用法：tr [选项]... SET1 [SET2]
Translate, squeeze, and/or delete characters from standard input,
writing 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 character
  -t, --truncate-set1     first truncate SET1 to length of SET2
      --help		显示此帮助信息并退出
      --version		显示版本信息并退出

SET 是一组字符串，一般都可按照字面含义理解。解析序列如下：

  \NNN	八进制值为NNN 的字符(1 至3 个数位)
  \\		反斜杠
  \a		终端鸣响
  \b		退格
  \f		换页
  \n		换行
  \r		回车
  \t		水平制表符
  \v		垂直制表符
  字符1-字符2	从字符1 到字符2 的升序递增过程中经历的所有字符
  [字符*]	在SET2 中适用，指定字符会被连续复制直到吻合设置1 的长度
  [字符*次数]	对字符执行指定次数的复制，若次数以 0 开头则被视为八进制数
  [:alnum:]	所有的字母和数字
  [:alpha:]	所有的字母
  [:blank:]	所有呈水平排列的空白字符
  [:cntrl:]	所有的控制字符
  [:digit:]	所有的数字
  [:graph:]	所有的可打印字符，不包括空格
  [:lower:]	所有的小写字母
  [:print:]	所有的可打印字符，包括空格
  [:punct:]	所有的标点字符
  [:space:]	所有呈水平或垂直排列的空白字符
  [:upper:]	所有的大写字母
  [:xdigit:]	所有的十六进制数
  [=字符=]	所有和指定字符相等的字符

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.

GNU coreutils online help: <http:///software/coreutils/>
请向<http:///team/zh_CN.html> 报告tr 的翻译错误
Full documentation at: <http:///software/coreutils/tr>
or available locally via: info '(coreutils) tr invocation'
[purpleenduer @ kylin ~ ]

[purpleendurer @ bash ~] echo -e "Windows95 1995 June\nWindows98 1998 August\nDOS 1981 May" > t.txt
[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~] cat t.txt | tr a-z A-Z
WINDOWS95 1995 JUNE
WINDOWS98 1998 AUGUST
DOS 1981 MAY
[purpleendurer @ bash ~] tr a-z A-Z < t.txt
WINDOWS95 1995 JUNE
WINDOWS98 1998 AUGUST
DOS 1981 MAY
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~] tr [:upper:] [:lower:] < t.txt
windows95 1995 june
windows98 1998 august
dos 1981 may
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~] tr -s "9" < t.txt 
Windows95 195 June
Windows98 198 August
DOS 1981 May
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~]  tr  "0-9" "C-L" < t.txt  > s.txt
[purpleendurer @ bash ~] cat s.txt
WindowsLH DLLH June
WindowsLK DLLK August
DOS DLKD May
[purpleendurer @ bash ~]  tr  "C-L" "0-9" < s.txt > r.txt
[purpleendurer @ bash ~] cat r.txt 
Windows95 1995 7une
Windows98 1998 August
1OS 1981 May
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~] tr 'a-zA-Z' 'n-za-mN-ZA-M' < t.txt > s.txt
[purpleendurer @ bash ~] cat s.txt
Jvaqbjf95 1995 Whar
Jvaqbjf98 1998 Nhthfg
QBF 1981 Znl
[purpleendurer @ bash ~] tr 'a-zA-Z' 'n-za-mN-ZA-M' < s.txt > r.txt
[purpleendurer @ bash ~] cat r.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] md5sum t.txt
95ffe6a8713a31e34ed3daffe500b628  t.txt
[purpleendurer @ bash ~] md5sum r.txt
95ffe6a8713a31e34ed3daffe500b628  r.txt
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
[purpleendurer @ bash ~] tr ' ' '\t' < t.txt
Windows95       1995    June
Windows98       1998    August
DOS     1981    May
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] echo -e "\n\nWindows2000\n\n\nwindows XP" >> t.txt
[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May


Windows2000


windows XP
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May


Windows2000


windows XP
[purpleendurer @ bash ~] tr -s "\012" < t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
Windows2000
windows XP
[purpleendurer @ bash ~]

[purpleendurer @ bash ~] cat t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May


Windows2000


windows XP
[purpleendurer @ bash ~] tr -s "\n" < t.txt
Windows95 1995 June
Windows98 1998 August
DOS 1981 May
Windows2000
windows XP
[purpleendurer @ bash ~]