'Else if'in bash scripting, often written as'elif', is used to check multiple conditions in your code. It is used with the syntax,if [firstStatement]; then... elif [secondCondition]; then... else. It’s a powerful tool that allows your scripts to make decisions based on various scen...
清单9. 用 if、then、else 计算表达式 [ian@pinguino ~]$ function mycalc () > { > local x > if [ $# -lt 1 ]; then > echo "This function evaluates arithmetic for you if you give it some" > elif (( $* )); then > let x="$*" > echo "$* = $x" > else > echo "$* = ...
syntax error near unexpected token then 同理,还有很多出错信息 比如 syntax error near unexpected token fi 等都是这样引起的. 5 if 后面一定要跟上 then. 同理 elif 后面一定要跟上 then. 不然提示出错信息: syntax error near unexpected token else top BASH IF http://lhsblog01.blog.163.com/blog/s...
file="./file" if [ -e $file ]; then echo "File exists" else echo "File does not exists" fi 1. 2. 3. 4. 5. 6. 7. Similarly for example we can use while loop to check if file does not exists. This script will sleep until file does exists. Note bash negator "!" which ne...
The syntax of the if statement in Bash is: if first-test-commands; then consequent-commands; [elif more-test-commands; then more-consequents;] [else alternate-consequents;] fi Tests commands in the bash if statement, and bash elif clauses, are executed in order until one test succeed....
A=10B=15if [ $A -eq $B ]then echo 'True'else echo 'False'fi 这是一个if条件判别语句(后面再细讲)。-eq判断运算符左右两边是否相等，如果是，则返回True，不然就返回False。关系判断运算符的基本格式是[ VAR1 OPERATOR VAR2 ]，用一个中括号括起来，这里有一点细节要注意，中括号和变量之间，...
-ge 大于等于,如:if [ "a"−ge"b" ] -lt 小于,如:if [ "a"−lt"b" ] -le 小于等于,如:if [ "a"−le"b" ] < 小于(需要双括号),如:(("a"<"b")) <= 小于等于(需要双括号),如:(("a"<="b")) > 大于(需要双括号),如:(("a">"b")) ...
SyntaxError :invalid syntax 2019-09-28 16:27 −1)忘记在 if , elif , else , for , while , class ,def 声明末尾添加 :(导致 “SyntaxError :invalid syntax”)该错误将发生在类似如下代码中:12if spam== 42 print('Hello!')2... 澜七玖 ...
SyntaxError :invalid syntax 2019-09-28 16:27 −1)忘记在 if , elif , else , for , while , class ,def 声明末尾添加 :(导致 “SyntaxError :invalid syntax”)该错误将发生在类似如下代码中:12if spam== 42 print('Hello!')2... 澜七玖 ...
Syntax of nested if statement if condition1 then Code block executed when condition1 is true if condition2 then # Code block executed when both condition1 and condition2 are true else # Code block executed when condition1 is true, but condition2 is false ...