bash："IF command"命令作为条件

bash："IF command"命令作为条件

 

 

 

 

一、说明

 

　　1、IF的条件部分，可以使用linux“命令”。

if command
then
    command if $?=0
else
    command if $?!=0
fi

 

 

 

 

二、代码

 

[root@rocky shell]# cat  if_command 
#!/usr/bin/env bash


# file_name = if_command


run()
{
        if $@
        then
                echo "os_running: ${@}"
        fi
}


list()
{
        if  ls -lh      # command as condition of if
        then
                echo
        fi
}




run $@

list


[root@rocky shell]# 
[root@rocky shell]# 

 

 

 

 

 

 

三、运行

 

 

[root@rocky shell]# cat  if_command 
#!/usr/bin/env bash


# file_name = if_command


run()
{
        if $@
        then
                echo "os_running: ${@}"
        fi
}


list()
{
        if  ls -lh      # command as condition of if
        then
                echo
        fi
}




run $@

list


[root@rocky shell]# 
[root@rocky shell]# 
[root@rocky shell]# ls
if_command
[root@rocky shell]# 
[root@rocky shell]# 
[root@rocky shell]# ./if_command "mkdir big"
os_running: mkdir big
total 4.0K
drwxr-xr-x 2 root root   6 Jan 29 00:01 big
-rwx--x--x 1 root root 192 Jan 28 23:59 if_command

[root@rocky shell]# 
[root@rocky shell]# 
[root@rocky shell]# ls
big  if_command
[root@rocky shell]# 
[root@rocky shell]# 
[root@rocky shell]# rm -rf big
[root@rocky shell]# 
[root@rocky shell]# 
[root@rocky shell]# ls
if_command
[root@rocky shell]# 
[root@rocky shell]# 

 

 

 

 

 

 

四、参考资料

 

　　1、　　Bash - Conditional structures if and case：　　https://docs.rockylinux.org/books/learning_bash/06-conditional-structures/