Daily Linux commands for Linux (1)-cat

Daily Linux (1)-cat

effect

Connect files and print to standard output

grammar

Command Line

cat [-AbeEnstTuv] [--help] [--version] [infilename] [>filename]

-AbeEnstTuv：参数

-v (show-nonprinting)：使用 ^ 和 M- 符号，除了 LFD 和 TAB 之外。
-E 或 --(show-ends) : 在每行结束处显示 $。
-T 或 --(show-tabs): 将 TAB 字符显示为 ^I。
-A, --show-all：等价于 -vET。
-e：等价于"-vE"选项；
-t：等价于"-vT"选项；
--help：查看帮助
--version：版本说明
infilename：读取文件名称，没有该参数默认从键盘输入，用于写文件
>filename：输出文件名称，没有该参数默认输出到终端显示

parameter

• Test file test.txt

  # 测试内容
  test	test1		
  test2
  
  
  test3
  

• -n (number): display each line number (including blank lines), starting from 1

  $cat -n text.txt
  
       1	test	test1
       2	test2
       3	
       4	
       5	test3
  

• -b (number-nonblank): same as -n, but does not contain blank lines

  $cat -b text.txt
  
       1	test	test1
       2	test2
  
  
       3	test3
  

• -s (squeeze-blank): merge continuous empty lines with one blank line

  $cat -s text.txt
  
  test	test1
  test2
  
  test3
  

• -v (show-nonprinting): directly read the bytes of the file and convert the special characters

  • Use '^' to input control characters except LFD and TAB
  • The character with the highest bit of each byte being 1 replaces the highest bit of each byte with 'M-'
  • Generally, this parameter can be used when the encoding format error occurs

  举例
  汉字:'学'
  UTF-8:16进制　E5 AD A6　2进制　11100101 10101101 10100110
  高1位转换:M-1100101 M-0101101 M-0100110
  后7位转换:M-eM--M-&
  

• -E (show-ends): display $ at the end of each line

  $cat -E text.txt
  
  test	test1$
  test2$
  $
  $
  test3$
  

• -T (show-tabs): display TAB characters as ^ I

  $cat -T text.txt
  
  test^Itest1
  test2
  
  
  test3
  

• -A: equivalent to -vET

• -e: equivalent to -vE

• -t: equivalent to -vT

Tips

• cat> filename is used to create a new file and edit the content, overwrite if the file name exists
• cat >> filename is used to create a new file and edit the content, append if the file name exists