linux系统内置命令可以通过以下两种方式查询:“cat --help” 或者“man cat”。


cat file_name 显示文件全部内容

cat -b file_name 显示文件非空行内容

cat -E file_name 在文件每行末尾显示$,常用于管道功能

cat -n file_name 显示内容和行号

Usage: cat [OPTION]... [FILE]...
Concatenate FILE(s) to standard output.

With no FILE, or when FILE is -, read standard input.

 -A, --show-all      equivalent to -vET
 -b, --number-nonblank  number nonempty output lines, overrides -n
 -e            equivalent to -vE
 -E, --show-ends     display $ at end of each line
 -n, --number       number all output lines
 -s, --squeeze-blank   suppress repeated empty output lines
 -t            equivalent to -vT
 -T, --show-tabs     display TAB characters as ^I
 -u            (ignored)
 -v, --show-nonprinting  use ^ and M- notation, except for LFD and TAB
   --help   display this help and exit
   --version output version information and exit

 cat f - g Output f's contents, then standard input, then g's contents.
 cat    Copy standard input to standard output.

GNU coreutils>
Usage: head [OPTION]... [FILE]...
Print the first 10 lines of each FILE to standard output.
With more than>
Usage: tail [OPTION]... [FILE]...
Print the last 10 lines of each FILE to standard output.
With more than>总结