readarray: readarray [-n count] [-O origin] [-s count] [-t] [-u fd] [-C callback] [-c quantum] [array] Read lines from a file into an array variable. A synonym for `mapfile'. readonly: readonly [-aAf] [name[=value] ...] or readonly -p Mark shell variables as unchan...
同时,可以通过read命令读取数组中的数据,并可以用来读取用户输入的密码。 Linux的read命令是用于从标准输入或者文件中读取一行内容并将其保存到一个变量中。它的使用非常灵活,可以用于交互式的输入,也可以用于从文件中读取内容。 ## 基本语法 “` read [options] [variable] “` ## 参数 –options:可以是以下选项...
read [-options] [variable] read命令用于从标准输入中读取一行,然后存储到变量中。如果没有给定变量名,则输入将存储在特殊变量REPLY中。 2. 交互式提示用户输入: read命令通常用于与用户交互,提示用户输入所需的数据。例如,可以在脚本中使用read命令来要求用户输入用户名、密码等信息。 3. 读取多个输入: read命令...
我们 可以使用命令 help readarray 来查看 readarray 命令的帮助信息。 purleEndurer @ bash ~ $ help readarray readarray: readarray [-n count] [-O origin] [-s count] [-t] [-u fd] [-C callback] [-c quantum] [array] Read lines from a file into an array variable. A synonym for `...
the line read is storedinthe REPLY variable.1213Options:14-a array assign the words read to sequential indices of the array15variable ARRAY, starting at zero16-d delim continueuntilthe first character of DELIM is read, rather17than newline18-e use Readline to obtain the lineinan interactive...
3. UsingreadWith awhileLoop If we want to read a file that contains a lot of data, we can useawhileloop andreadthe file line-by-line into a variable. We can then use the variable inside ourwhileloop’s scope: #!/bin/shcatpackages.txt |whilereadpkg;doecho"$pkg"done ...
To change permissions, use the chmod command. First, pick the set of permissions that you want to change, and then pick the bit to change. For example, to add group (g) and world (o, for “other”) read (r) permissions to file, you could run these two commands: ...
Disks can be easily split up into blocks of data. Because a block device’s total size is fixed and easy to index, processes have random access to any block in the device with the help of the kernel. 程序以固定的块大小从块设备中访问数据。 上述示例中的sda1是一个磁盘设备,也是一种块...
file FILENAME ln 创建连接文件。 ln [-fs] SRC DST -f:强制创建。 -s:创建软连接,缺省则为创建硬连接。 DST为新建的文件。 ls 查看文件/目录。 ls [-aAdFhlrRSt --color={always|auto|never} --full-time --time={atime|ctime}] [NAMEGLOB] ...
(For example, the bash shell reads the PS1 variable before displaying the prompt.) Shell可以存储临时变量,称为Shell变量,其中包含文本字符串的值。 Shell变量在脚本中跟踪值非常有用,而且一些Shell变量可以控制Shell的行为方式(例如,bash Shell在显示提示符之前会读取PS1变量)。