Awk from entry to earth (15) awk executes external commands

External commands here , Refer to shell command .

Method 1

If you don't need to get the output of the command but just need to execute the command, you can use system() function .

#!/usr/bin/awk -f
BEGIN {
    

system("touch test");

}

The command string must consist of “” Cover up .

It can even judge whether the command was successfully executed ：

BEGIN{
    
    fold = "/tmp/test";
 
    #  Invoking system commands mkdir Create folder 
    res = system("mkdir " fold);
    print("res: " res);
    if ( 0 == res ) {
    
            print(" Folder created successfully ");
    }
 
    #  Create the same folder again 
    res = system("mkdir " fold);
    print("res: " res);
    if ( 0 != res ) {
    
        print(" Folder creation failed ");
    } 
}
{
    
}
END{
    
}

Method 2

"ls" | getline var

var Is a variable name. , It can be omitted , It is equivalent to assigning the execution result of the command to var.