and wait for a username prompt.spawn telnet$remote_serverexpect"username:"# Send the username, and then wait for a password prompt.send"$my_user_id\r"expect"password:"# Send the password, and then wait for a sh
# Save the PID of the scp of a given server for later28done29# Iterate through all the servers and:30# Wait for the return code of each31# Check the exit code from each scp32forserverin${!server_pid[*]};do33wait${server_pid[$server]}34test$?-ne0&&echo"ERROR: Copy from$server...
12. Inside each script, capture the return code of each line command One way to determine the success or failure of the function testing is by counting the line commands that have failed, that is, that have a return code different than 0. The variable "$?" provides the return code of ...
You can assign data to a variable using the equals sign (=). The data you store in a variable can either be a string or a number. Let’s create a variable now on the command line: chapter_number=5 The variable name is on the left hand side of the equals sign, and the data whic...
解释型语言也被称作“脚本语言”。执行这类程序时,解释器(interpreter)需要读取我们编写的源代码(source code),并将其转换成目标代码(object code),再由计算机运行。因为每次执行程序都多了编译的过程,因此效率有所下降。 使用脚本编程语言的好处是,它们多半运行在比编译型语言还高的层级,能够轻易处理文件与目录之类的...
In the exercise above, The "date" command is used to display the current date and time. Command substitution $(...) is used to capture the output of the "date" command and store it in the variable 'currentDateTime'. The "echo" command prints the value of the variable 'currentDateTime...
See also: When calling a function, quote the variable otherwise bash will not see the string as atomic. The separator is variable $IFS. There is: ... Bash - (Builtin|Intern|System|Reserved|Shell) variable name Reserved variable name are named that have a special meaning for the bash ...
This is an alternative to sed, awk, perl and other tools. The function below works by finding all leading and trailing white-space and removing it from the start and end of the string. The : built-in is used in place of a temporary variable....
How can I check the exit code of the last command? You can check the exit code of the last command by using the special variable$?. What is the purpose of thetrapcommand? Thetrapcommand allows you to define actions that should occur when a script exits, which is useful for cleanup tas...
To capture a command's output while using it as a condition, use an assignment as the condition (but see below on not using local on assignments):if output="$(command)"; then … fi If at all using the exit status variable $? with errexit, it is of course no substitute for the ...