Android adb Shell learning Experience (iv)

Sub in 1.awk

The sub is the replacement function. Forms such as

Sub (/1/, "", $)

Replace the first 1 of the second variable with an empty one, if the sub is replaced with Gsub. The entire 1 is replaced.

-F in 2.awk

Delimiter, default feel space

Fs,ofs in 3.awk

FS is the column delimiter and OFS is the output column delimiter. The blank space of the tacit feeling

4.$#: Number of parameters for this program

5.$0: The running name of this program

6. $n: The nth number of the program. n=1..9

7.$*: The total number of parameters for this program, this option can be more than 9

8.$$: PID of this program (the current process ID number of the script execution)

9.$!: Performs the PID of the previous background instruction (process ID number of the last process executed in the background)

10.$: Run the return value of the previous instruction (shows the exit status of the last command.) 0 indicates no error. Any other value indicating an error)

Android adb Shell learning Experience (iv)