条件表达式提供了其他非常多的选项,读者可以在Bash手册中搜素关键字CONDITIONAL EXPRESSIONS进行查阅。注意,在上面的例子中[[的后边,以及]]的前边都有一个空格,这个空格一方面是为了可读性和美观,另一方面是,唔,因为必须这么做,否则Bash会认不出来这是个条件表达式[[ ]]符号,而会理解为[[-e命令或者file_a]]变量之...
break和continue内置命令(详见 “4.1 Bourne Shell 内置命令”)可以用来控制循环的执行。 3.2.5.2 条件结构(conditional constructs) 3.2.5.2.1IF if命令的语法是: AI检测代码解析 if test-commands; then consequent-commands; [elif more-test-commands; then more-consequents;] [else alternate-consequents;] fi...
# Check status and health /etc/init.d/opsware-sas health > /dev/null 2>&1 HEALTH_CODE=$? /etc/init.d/opsware-sas status > /dev/null 2>&1 STATUS_CODE=$? if [[ $HEALTH_CODE -ne 0 ]] || if [[ $STATUS_CODE -ne 0 ]]; then printf "This is the conditional line" # Code ...
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Bash Scripting and Conditional Statements Expanding Horizons: ‘Else If’ in Larger Bash Scripts Wrapping Up: Mastering ‘Else If’ in Bash Scripting Understanding ‘Else If’ in Bash Scripting ‘Else if’, or ‘elif’ as it’s often written in bash, is a fundamental part of conditional state...
shell bash：在if语句中使用条件AND OR你不需要for循环，也不需要[[...]]条件结构，你只需要模式匹配...
Execute conditional command. Returns a status of0or1depending on the evaluation of the conditional expression EXPRESSION. Expressions are composed of the same primaries used by the `test'builtin, and may be combined using the following operators:( EXPRESSION ) Returns the value of EXPRESSION! EXPRE...
Evaluate conditional expression. Exits with a status of 0 (true) or 1 (false) depending on the evaluation of EXPR. The behavior of test depends on the number of arguments. Read the bash manual page for the complete specification. String operators: ...
Using while, $* and $@. Segment 4: Applying Pattern Matching substitution Length: 30 minutes Modifying strings with pattern matching substitution Modifying strings with tr, awk and sed 10-minute break Segment 5: Using conditional structures Length: 50 minutes Using if then else Using logical operat...
In this example, we have an arraynumberswith five elements. We use a ‘for’ loop to iterate through each element in the array. Inside the loop, we have a conditional ‘if’ statement that checks if the current number is even or odd (using the modulus operator%). Depending on the resu...