read num if [ $num -gt 10 ]; then echo "输入的数字大于 10." else echo "输入的数字不大于 10." fi 这里的-gt是一个表达式,用来判断输入的数字是否大于 10,除了-gt,Bash 还提供了其他一些常用的比较运算符: -eq:等于(equal) -ne:不等于(not equal) -lt:小于(less than) -le:小于等于(less ...
1. 显示脚本的执行的详细步骤: sh -x shellScript.sh 1. 2. 判断一条指令是否执行成功 netstat -lpntu | grep 80 echo $? #If output=0 --> 执行指令成功 #If output=1 --> 执行指令不成功 1. 2. 3. 4. if 语句 格式: if [ Param1 逻辑运算符 Param2 ] then comma...
Bash, short for "Bourne Again SHell," is a powerful scripting language used in Unix-based operating systems. One of the fundamental constructs in Bash programming is the if statement. The if statement allows you to control the flow of your script based on specific conditions. In this article,...
返回状态值可以使得程式与程式之间利用返回状态值可以使得程式与程式之间利用返回状态值可以使得程式与程式之间利用shellshellshellscriptscriptscript来结合的可能性大增利用小程式透过来结合的可能性大增利用小程式透过来结合的可能性大增利用小程式透过shellshellshellscriptscriptscript来完成很杂的工作 Linux程式设计- ...
How to do string comparison and check if a string equals to a value? How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not equal) How to use the BASH_REMATCH variable with...
可以cp到脚本配置文件 /etc/init.d 里面;但需要先给其权限;然后再拷贝;然后在命令行键入chkfig -add script.sh 运行;则可生效 # prog=`basename $0` $0是从当下目录到其有$0脚本的完全路径 lockfile=/var/lock/subsys/$prog if [ $# -lt 1 ]; then echo "Usage: $prog {start|stop|restart|status}...
[ ARG1 OP ARG2 ] “OP” is one of -eq, -ne, -lt, -le, -gt or -ge. These arithmetic binary operators return true if “ARG1” is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to “ARG2”, respectively. “ARG1” and “AR...
1. File-based conditions: With the double-parenthesis syntax, you can use the following conditions: 5. Double-parenthesis syntax conditions: After this dry information load, here’s a bit of explanation for those who want to know more…
/bin/bashif[ $# -ne2];thenecho"Please input exact two number arguments."exit1fiif[ $1-eq $2];thenecho"Number $1 and $2 are equal."elif[ $1-gt $2];thenecho"The greater is $1."elseecho"The greater is $2."fi 编写一个脚本,接收一个用户名作为参数,并判断其奇偶性。
批处理(Batch):用户事先写一个Shell脚本(Script),其中有很多条命令,让Shell一次把这些命令执行完,而不必一条一条地敲命令,而由于 shell 本身就被看做是一种脚本语言,也有变量和流程控制语句,因此它具备的功能远比 windows 下的批处理要强大。 常用shell ...