当我们运行这个脚本时,如果小于 150,它将打印数字。 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 ……...
*)statementnesaccase、in 和 esac 都是 Shell 关键字，expression 表示表达式，pattern 表示匹配模式。e...
2. How do I write an if statement in a shell script? Writing an if statement in a shell script involves specifying a condition and the actions to take if the condition is true. Here’s the basic syntax: if[condition];then# code to execute if condition is trueelse# code to execute if...
A nested if statement is an if statement inside a clause of another if statement. Nothing prevents multiple levels of if statement in a shell script and in Bash. if first-test-commands; then if second-level-test-commands; then consequent-commands; else second-level-alternate-consequents; [eli...
In this example, the script first checks if ‘a’ is greater than ‘b’. If it’s not, it moves on to the ‘elif’ statement to check if ‘a’ is greater than ‘c’. If neither condition is met, it executes the ‘else’ statement, which in this case, prints ‘a is not greate...
for变量名in取值列表do命令 done 语法二: for ((expr1;expr2;expr3));do 命令列表 done 实例: #提前准备好用户的文件[root@VM_0_10_centos shellScript]#vi username.txttest01 test02 test03 test04 test05 test06#vi example.sh#!/bin/bashread -p"请输入用户密码:"PASSWDforUNAMEin`cat username....
shell执行了if行中的pwd命令。由于退出状态码是0,它就又执行了then部分的echo语句。 下面是另外一个例子。 1$catif-then2.sh2#!/bin/bash3#testing a bad command4ifIamNotaCommand5then6echo"it worked"7fi89echo"we are outside thie if statement"10$chmoda+xif-then2.sh11$ ./if-then2.sh12....
bash shell if-statement while-loop m3u 我正在编写一个脚本来解析m3u文件。目标是检索变量标记和url。我用这个文件做了测试。 #!/bin/bash echo "name,tvg-id,tvg-name,tvg-country,group-title,languages,url" while IFS= read -r line; do tags_detect="$(echo "$line" | grep -Eo '^#EXTINF:')...
Example of running bash script with logical operators in if statement 🏋️ 练习时间 让我们做一些练习吧 😃 练习1:编写一个 Bash Shell 脚本,检查作为参数提供给它的字符串的长度。如果未提供参数,它将打印 “empty string”。 练习2:编写一个 Shell 脚本来检查给定文件是否存在。你可以提供完整的文件路...
8 shell if elif else 2019-12-19 18:59 −if 语句的判断条件,从本质上讲,判断的就是命令的退出状态。 语句语句格式同一行书写注意点用例1用例2 if 语句 if conditionthen statement(s)fi if condition; then statement(s... 声声慢43 0 590