You can have awhileloop to keep checking for that directory's existence and only write a message while the directory does not exist. If you want to do something more elaborate, you could create a script and show a more clear indication that the loop condition became true: #!/bin/bashwhil...
For example, you can add the nested loop example to a Bash script to improve its readability, like this: $ vim copy_web_files.sh # !/bin/bash for i in file{1..3};do for x in web{0..3};do echo "Copying $i to server $x" scp $i $x done done When you save and execute ...
1.1 认识 for ... do ... done 昨天刚学过while,until的循环方式 -->Linux 之 shell script -- loop(不定循环) :符合循环条件便可以无限得循环执行指定的“程序段”,我们便称为不定循环。今天学习与不定循环相对应的for循环,这种语法则是已经知道要进行几次循环的状态。 for ... do ... done的语法结...
If you don’t specify the keyword “in” followed by any list of values in the bash for loop, it will use the positional parameters (i.e the arguments that are passed to the shell script). $ cat for3.sh i=1 for day do echo "Weekday $((i++)) : $day" done $ ./for3.sh ...
Linux Bash Script loop shell 编程之流程控制 for 循环、while 循环和 until 循环 for var in item1 item2 ... itemN do command1 command2 ... commandN done 1. 2. 3. 4. 5. 6. 7. for var in item1 item2 ... itemN; do command1; command2… done; ...
exit # exit script fi echo keep running ~/bin/process_data # do some work done 如果要退出循环而不是退出脚本,请使用break命令而不是exit。 #!/bin/bash while true do if [ `date +%H` -ge 17 ]; then break # exit loop fi echo keep running ...
如果命令被信号中断, Bash 返回状态码 128 ,加上信号码。最终,用户的错误码应该大于 191 , Bash 返回的错误码为 63 。信号码列在附录 E :信号。 if test ! -x “$who” ; then printf “$SCRIPT:$LINENO: the command $who is not available –“/ ...
fruit=orange; and on the third and final iteration,fruit=pear. Once it has completed the loop, the script continues normal execution with the next command after thedonestatement. In this case, it ends by saying “Let’s make a salad!” to show that it has ended the loop, but not the...
linux shell script Hello World #!/bin/bashecho'Hello Bash World' for loop in one line 一行实现循环调用 foriin{1..5};doCOMMAND1-HERE&&COMMAND2-HERE;done 定义function 你可以用function 函数名{} 或者 直接函数名 #!/bin/bash#usage(){functionusage(){echo"sleep seconds"}if[$#== 1 ];then...
[root@www shell-script]# cat c_for02.sh#!/bin/bashfor((i=1,j=100;i<=10;i++,j--))doecho"i=$ij=$j"done 1. 2. 3. 4. 5. 6. for的无限循环 #!/bin/bashfor((i=0;i<1;i+=0))doecho"infinite loop"done 1. 2.