The loop structure is one of the key components of every programming language including Bash. They are used to repeat the specified instructions against a condition. Frequently employed loop structures in Bash
在Bash脚本,有3种类型loops:for loop,while loop, 和until loop. 这三个用于迭代值列表并执行一组给定的命令。 Bash For 循环语法 for loop遍历一系列值并执行一组命令。 For loop采用以下语法: forvariable_name in value1 value2 value3..ndocommand1 command2 commandn done 1. 2. 3. 4. 5. 6. Ba...
/bin/bashFILE=$1#read$FILEusing thefiledescriptorsexec3<&0exec0<$FILEwhilereadlinedo# use$linevariable to process lineecho$linedoneexec0<&3 You can easily evaluate the options passed on the command line for a script using while loop: ... .. while getopts ae:f:hd:s:qx: option do case...
while read line do # use $line variable to process line echo $line done exec 0<&3 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. You can easily evaluate the options passed on the command line for a script using while loop: ... .. while getopts ae:f:hd:s:qx: option do case "...
在Bash脚本中有3个基本的循环结构,for循环,while循环,until循环。...本教程解释了Bash中while循环的基础知识,以及用于改变循环流的break和continue语句。...Bash while 循环 只要给定条件的计算结果为true,while循环就会使用一组给定的命令执行未知次数。...
while true do echo "endless loop" done 可以在 if/then 中作占位符: #!/bin/bash condition=5 if [ $condition -gt 0 ] #gt表示greater than,也就是大于,同样有-lt(小于),-eq(等于) then : # 什么都不做,退出分支 else echo "$condition" ...
while IFS= read -r _; do ((count++)) done < "$1" printf '%s\n' "$count" } 用法示例: $ lines ~/.bashrc 48 $ lines_loop ~/.bashrc 48 计算目录中的文件或目录 这是通过将glob的输出传递给函数然后计算参数的数量来实现的。 示例功能: ...
Bash For Infinite Loop In one Line # for (( ; ; )); do echo "Hello World!"; done # while true; do echo "Hello World!"; done # while :; do echo "Hello World!"; done Bash For Loop In One Line with Files # for i in *; do echo "Found the following file: $i"; done ...
# While loop counter=1 while [[ $counter -le 5 ]]; do echo “Counter: $counter” counter=$((counter+1)) done “` 以上是编写 Bash 脚本的一些建议和示例。当然,还有很多其它功能和语法可以用于编写 Bash 脚本,这只是一个入门级的介绍。要深入了解 Bash 脚本编写,请参考 Bash 的官方文档或相关的教...
Adding a for loop to a Bash script Runningforloops directly on the command line is great and saves you a considerable amount of time for some tasks. In addition, you can includeforloops as part of your Bash scripts for increased power, readability, and flexibility. ...