cat
约 357 字大约 1 分钟
cat 显示较少内容
①、命令名称:
②、英文原意:
③、命令所在路径:
④、执行权限:所有用户
⑤、功能描述:在 Linux 系统下使用 cat 命令进行多个小文件的合并也很方便
⑥、语法:
cat [选项] [文件名]
-b: #空行不计入行号的统计
-n: #显示行号
-e: #以$字符作为每行的结尾
-t: #显示TAB字符(^I),禁用制表符
⑦、使用实例
# 合并文件
[root@admin home]# cat /data/users_* > users.sql
[root@admin home]# cat demo.txt
sdfsdfsdf
1354354
34sdr23424sdfs
[root@admin home]# cat -n demo.txt
1 sdfsdfsdf
2
3 1354354
4
5 34sdr23424sdfs
6
[root@admin home]# cat -b demo.txt
1 sdfsdfsdf
2 1354354
3 34sdr23424sdfs
[root@admin home]# cat -T demo.txt
sdfsdfsdf
1354354
34sdr23424sdfs
# 替换全部内容
cat -s <<EOF > /home/test/k8s.conf
vm.swappiness=0
EOF
# 追加内容
cat -s <<EOF >> /home/test/k8s.conf
vm.swappiness=0
EOF
⑧、帮助信息
# 帮助信息
$ cat --h
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
Examples:
cat f - g Output f's contents, then standard input, then g's contents.
cat Copy standard input to standard output.
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Full documentation at: <http://www.gnu.org/software/coreutils/cat>
or available locally via: info '(coreutils) cat invocation'