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This article is about how shell works with expect to write bulk scp scripts. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

When deploying a task, a necessary process is to send files, such as installation packages, to a large number of servers. Although Yuge's scripts are available: python scripts written through the ssh and scp functions provided by the paramiko module. But I am still in fear of python (although I have worked hard to learn in my spare time), so I used a combination of shell and expect scripts to write this batch scp scripting tool.

Expect is used to automate command-line interactive tasks in a linux environment, such as scp, ssh, and other tasks that require users to manually enter passwords and then confirm. With this tool, you can define the situations you may encounter during scp, and then write the corresponding processing statements, and you can automatically complete the scp operation.

If you need expect tools, you can use package management tools such as apt-get or pacman in the linux environment to obtain the installation, or go to the website of the expect open source project: http://expect.sourceforge.net/.

After installing expect, you can try to complete the scp task for a single server using the following code:

#! / usr/bin/expectset timeout 10set host [lindex $argv 0] set username [lindex $argv 1] set password [lindex $argv 2] set src_file [lindex $argv 3] set dest_file [lindex $argv 4] spawn scp $src_file $username@$host:$dest_file expect {"(yes/no)?" {send "yes\ n" expect "* assword:" {send "$password\ n"} "* assword:" {send "$password\ n"} expect "100" expect eof

Notice that the first line of the code specifies the path to the expect, which is the same as the shell script, which specifies where to find the appropriate startup program when the program is executed. At the beginning of the code, the timeout time is set to 10 seconds. If you encounter an exception that is not specified in the code during the execution of the scp task, the execution of the script will automatically terminate after waiting for 10 seconds.

As you can see from the first few lines of the above code, I set five parameters for this script that need to be entered manually: the IP of the target host, the user name, password, the local file path, and the file path in the target host. If you save the above script as an expect_scp file, you need to enter commands according to the following specifications when executing under shell:

. / expect_scp 192.168.75.130 root 123456 / root/src_file / root/dest_file

After the above command is executed, the src_file file in the local / root directory will be copied to / root in the host 192.168.75.130 with the username root and password 123456, and the source file will be renamed dest_file.

Spawn represents the statement executed at the local terminal. After the statement starts execution, the expect begins to capture the output information of the terminal and then makes the corresponding operation. The captured (yes/no) content in the expect code is used to save the key the first time the target host is accessed. With this sentence, scp's task reduces the number of interruptions. The expect eof at the end of the code corresponds to spawn, indicating the termination of capturing the output information of the terminal.

With this expect code, you can only complete the scp task for a single remote host. If you need to implement the task of batch scp, you need to write another shell script to call the expect script.

Shell script:

The code is as follows:

#! / bin/sh

List_file=$1

Src_file=$2

Dest_file=$3

Cat $list_file | while read line

Do

Host_ip= `echo $line | awk'{print $1}'`

Username= `echo $line | awk'{print $2}'`

Password= `echo $line | awk'{print $3}'`

Echo "$host_ip"

. / expect_scp $host_ip $username $password $src_file $dest_file

Done

Three parameters are specified: the location of the list file, the local source file path, and the remote host destination file path. It is important to note that the list file specifies the remote host ip, user name, and password, which needs to be written in the following format:

IP username password

Separated by a space or tab key, the information of multiple hosts needs to be written to multiple lines, such as:

192.168.75.130 root 123456

192.168.75.131 knktc testpass

This specifies the information for the two remote hosts. Note that if there are special characters such as "$" and "#" in the remote host password, you need to precede these special characters when writing the list file, otherwise expect will enter the wrong password during execution.

For this shell script, save it as a batch_scp.sh file, put it in the same directory as the expect_scp file and list file (defined as hosts.list file) you just saved, and enter the command in the following way when executing:

. / batch_scp.sh. / hosts.list / root/src_file / root/destfile

With these two script files, you can simply complete the task of batch scp.

In fact, the task of bulk scp is not difficult, but the task of bulk ssh may run into trouble.

Thank you for reading! This is the end of this article on "how to combine shell with expect to write batch scp scripts". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

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