在GNU bash 在线帮助手册的 “3.2.1 Simple Commands” 小节介绍了简单命令的概念: A simple command is the kind of command encountered most often. It’s just a sequence of words separated by blanks, terminated by one of the shell’s control operators (see Definitions). The first word generally ...
commands; statements; end=$(date +%s) difference=$((end - start)) echo time taken to execute commands is $difference seconds 2.工作原理 3.补充内容 在脚本中推迟执行一段时间,可以用sleep;$sleep no_of_seconds.例如,下面的脚本就使用tput和sleep从0开始计数到40: #!/bin/bash #filename:sleep.sh...
-x Mark namesforexporttosubsequent commands via the environment.Using`+' instead of `-' turns off the attribute instead, with the exceptions that +a and +A may not beusedtodestroy array variablesand+r willnotremove thereadonlyattribute.Whenusedina func‐ tion,declareandtypeset makeeachname lo...
AI代码解释 echo ${my_array[1]} 如下将返回最后一个元素,输出:value 4: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 echo ${my_array[-1]} 如下将输出数组中元素的总数,将输出:4: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 echo ${my_array[@]} 9. Bash 条件表达式 在计算机科学...
declare -A example_array=(["key1"]="value1", ["key2"]="value2", ["key3"]="value3") The second method is harder to read but creates an array and elements in a single line. In both cases, the commands do not print a response. ...
commands } 这是一个使用带参数的函数的 Bash 脚本样例: #!/bin/bash sum{ sum=$(($1+$2)) echo"The sum of $1 and $2 is: $sum" } echo"Let's use the sum function" sum15 如果你运行该脚本,你将看到以下输出: Let's use the sum function ...
# number of arguments passed to the bash script echo Number of arguments passed: $# ' -> echo Number of arguments passed: $#' 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. / Bash Scripting Tutorial 5. Executing shell commands with bash ...
Table of Contents How to use On the web From your terminal In your editor In your build or test suites Installing Compiling from source Installing Cabal Compiling ShellCheck Running tests Gallery of bad code Quoting Conditionals Frequently misused commands ...
function name { COMMANDS ; } or name > variables - Names and meanings of so> getopts optstring name [arg] wait [id] hash [-lr] [-p pathname] [-dt] [name > while COMMANDS; do COMMANDS; done help [-dms] [pattern ...] { COMMANDS ; } ...
$?" # 上一个命令的退出状态 echo "current shell process ID: \$$ $$" # 执行当前 bash 脚本的进程ID sleep 10 & # & 符号的主要作用是将命令放入新的子进程执行, 主脚本会立即执行后续命令 echo "process ID of recent backend commands: \$! $!" # 返回最近一个后台命令的进程 ID sleep 1 ...