If-statement-Bash-Script-Example if-else Statement 除了普通的 if 语句之外,我们还可以用 else 块扩展 if 语句。基本思想是,如果语句为真,则执行 if 块。如果语句为假,则执行 else 块。 Syntax : if [ condition_command ] then command1 command2 …….. last_command else command1 command2 …….. ...
/bin/bash3#testing a bad command4ifIamNotaCommand5then6echo"it worked"7fi89echo"we are outside thie if statement"10$chmoda+xif-then2.sh11$ ./if-then2.sh12./if-then2.sh: line3: IamNotaCommand: command not found13we are outside thieifstatement14$ 在这个例子中,我们在if语句行故意...
ifcondition;thenstatement(s)fi 请注意 condition 后边的分号;，当 if 和 then 位于同一行的时候，这...
[ -z s2 ] (true if s2 has a length of 0, otherwise false) Example Script number.sh #!/bin/bash echo -n “Enter a number 1 < x < 10: " read num if [ “$num” -lt 10 ]; then if [ “$num” -gt 1 ]; then echo “$num*$num=$(($num*$num))” else echo “Wrong i...
Case statement is similar to if statement with multiple elif. case statement in bash script expands the expression and then tries to to find the match with all the patterns. When a match is found then all the statements will be executed till the double semicolon (;;). In case it does ...
Use if statement in bash Let's create a script that tells you if a given number is even or not. Here's my script namedeven.sh: #!/bin/bash read -p "Enter the number: " num mod=$(($num%2)) if [ $mod -eq 0 ]; then ...
then statement3 . fi fi If statement and else statement could be nested in bash. The keyword “fi” indicates the end of the inner if statement and all if statement should end with the keyword “fi”. The “if then elif then else fi” example mentioned in above can be converted to th...
Using nested if statements in bash You can also use an if statement within another if statement. For example, take a look at the followingweather.shbash script: #!/bin/bash TEMP=$1 if [ $TEMP -gt 5 ]; then if [ $TEMP -lt 15 ]; then ...
Statement(s) to be executed if expression 2 is true elif [ expression 3 ] then Statement(s) to be executed if expression 3 is true else Statement(s) to be executed if no expression is true fi 二、if语句的运算符 必须记得:运算符和表达式之间必须有空格,例如2+2是不正确的,它应该写成2 +...
问在bash中使用内联if-statement添加命令参数ENexport export命令将会使得被 export 的变量在运行的...