/bin/bash # 方法一:直接赋值 array1=("value1" "value2" "value3") # 方法二:使用索引赋值 array2[0]="value1" array2[1]="value2" array2[2]="value3" # 方法三:从字符串分割赋值 string="value4 value5 value6" array3=($string) # 方法四:使用read命令赋值 echo "Enter values separated...
为什么"${foo[@]}"没有扩展到单个字符串? 我如何使上面的directly情况表现为via variable情况? 请解释构造${foo[*]}和${foo[@]}实际上是什么,以及引用操作对它做了什么。 这里发生了什么? 为什么“${foo[@]}”不扩展为单个字符串? 因为这是明确定义的行为,也是非常有用的行为。当由@索引的array-valued...
在Bash命令行中生成ASCII代码2和3,可以使用printf命令。printf命令允许您格式化输出字符串,并将其发送到标准输出。以下是如何在Bash命令行中生成ASCII代码2和3的方法: 代码语言:bash 复制 printf "\002" printf "\003" 这将分别输出ASCII代码2和3的字符。 ASCII代码2和3分别是控制字符,通常用于控制终端和打印机等...
array()created an empty array calledarray. IFS=Internal Field Separatoris used to specify a delimiter (which is whitespace in my case). array+=("$line")the line variable stores the value of each line in the file and using this argument, it gets stored in an array. ...
While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites. It makes canonical use of exit codes, so you can just add ashellcheckcommand as part of the process. For example, in a Makefile: ...
When no array variable name is provided to the mapfile command, the input will be stored into the $MAPFILE variable. Note that the mapfile command will split by default on newlines character but will preserve it in the array values, you can remove the trailing delimiter using the -t ...
To delete an associative array, use theunsetcommand and provide the array name: unset example_array The command removes the array variable and all the elements. Conclusion After reading this guide, you learned about associative arrays in Bash and how to use them. The feature appears in Bash ve...
${variable:pos}: 偏移pos个字符,取余下的子串 name=jerry,name:2结果为rryname:2结果为rry{variable:pos:num}: 偏移pos个字符,取num个字符长度的子串 name=‘hello world’, ${name:2:5}结果为“llo w” 字符串处理,将来在bash中经常用的
useradd $1 fi if之双分支 语句结构: if 测试条件;then 选择分支1 else 选择分支2 fi 两个分支仅执行其中之一 例:通过命令行给定一个文件路径,而后判断:如果此文件中存在空白行,则显示其空白行的总数;否则,则显示无空白行; if grep "^[[:space]]*""1 &> /dev/null; then ...
显示所有的环境变量,如果你想获取某个变量的详细信息,使用echo $VARIABLE_NAME. export Example: $exportSHELL=/bin/zsh AWS_HOME=/Users/adnanadnan/.aws LANG=en_US.UTF-8 LC_CTYPE=en_US.UTF-8 LESS=-R $echo$SHELL/usr/bin/zsh b.whereis ...