2 read使用实例 2.1 简单读取 $ read yourname tina $ echo $yourname tina 2.2 -p 参数,允许在 read 命令行中直接指定一个提示 $ read -p "input your name:" username input your name:tina $ echo $username tina 输入多个变量 1 #!/bin/bash 2 # entering multiple variables 3 4 read -p "...
基本的读取:read命令从标准输入(键盘 )或另一个文件描述符中接受输入。 生成提示的echo命令使用了-n选项 。 该选项不会在字符串末尾输出换行 ,允许脚本用户紧跟其后输入数据,而不是下一行。 实际上,read命令包了-p ,允许你直接在read命令行指定提示符 。 超时:-t 选项指定了read命令等待输入的秒数。当计时器...
First, we’ll discuss the classic C-style syntax method. After that, we’ll explore the nested loop method to use multiple variables in aforloop, followed by a discussion on custom delimiter approach with aforloop. Lastly, we’ll look into the use of thereadcommand withwhile. 2. Using ...
as we discussed in the previous section. You could also ask users to type in a string on the command line by temporarily stopping the execution of your program using thereadcommand. Let’s a write a small script where
while IFS= read -r _; do ((count++)) done < "$1" printf '%s\n' "$count" } 1. 2. 3. 4. 5. 6. 7. 8. 用法示例: $ lines ~/.bashrc 48 $ lines_loop ~/.bashrc 48 1. 2. 3. 4. 5. 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。
Attempting to change the value of the read-only variable results in an error. declare testvar="50"Copy Arrays Bash variables can have more than one value. To assign multiple values to a single bash variable, convert it to an array by typing: ...
whileread-r line;doprintf'%s\n'"$line"done<"file" 循环遍历文件和目录 不要用ls。 # Greedy example.forfilein*;doprintf'%s\n'"$file"done# PNG files in dir.forfilein~/Pictures/*.png;doprintf'%s\n'"$file"done# Iterate over directories.fordirin~/Downloads/*/;doprintf'%s\n'"$dir"...
HOSTFILE Contains the name of a file in the same format as /etc/hosts that should be read when the shell needs to complete a hostname. The list of possible hostname completions may be changed while the shell is running; the next time hostname completion is attempted after the value is ...
Nota bene: Avoid running nvm while the tests are running.Environment variablesnvm exposes the following environment variables:NVM_DIR - nvm's installation directory. NVM_BIN - where node, npm, and global packages for the active version of node are installed. NVM_INC - node's include file ...
Used to run multiple commands together.| > Used to send output to a file. >> Used to append output to a file. ; Used to separate multiple commands. < Used to get input from a file. ~ Expands to the home directory. ~/.bashrc Read by every non-login shell. /etc/profile Executed ...