The IF condition for Linux programming bash

Bash Script Programming:
Programming Languages:
Sequential execution
Select Execute
Loop execution

Select Execute:
If judging condition
Then
Branch code with true condition
Fi

if judgment condition; Then
Branch code with true condition
Else
The condition is a false branch code
Fi

Write a shell if the user does not exist, add the user, and the existing information is printed.

#!/bin/bash

If [$#-lt 1]; Then
echo "At least one"
Exit 1
Fi

If ID $ &>/dev/null; Then
echo "$ exixts"
#exit 0 indicates success
Exit 0
Else
Useradd $

[$?-eq 0] && echo "$" | passwd--stdin $ &>/dev/null && Exit 0 | | Exit 1
Fi

Usage
chmod +x a.sh
SH a.sh xiaoming

This article is from the "Liang blog" blog, make sure to keep this source http://7038006.blog.51cto.com/7028006/1827893

The IF condition for Linux programming bash