What spawns Pexpect?

What spawns Pexpect?

Pexpect is a Python module for spawning child applications and controlling them automatically. Pexpect can be used for automating interactive applications such as ssh, ftp, passwd, telnet, etc. It can be used to a automate setup scripts for duplicating software package installations on different servers.

How do you use a Pexpect module?

Approach:

1. Import pexpect.
2. spawn a child with pexpect.
3. FTP client asks for the user name.
4. Send the username to child process with sendline method.
5. Then the FTP client asks for the password.
6. Then the serve logged in.
7. Detect whether you can send command to the FTP server by the presence of ‘ftp> ‘.

What is Pty spawn?

pty. spawn (argv[, master_read[, stdin_read]]) Spawn a process, and connect its controlling terminal with the current process’s standard io. This is often used to baffle programs which insist on reading from the controlling terminal.

What is Python Import Pty?

The pty module defines operations for handling the pseudo-terminal concept: starting another process and being able to write to and read from its controlling terminal programmatically. Pseudo-terminal handling is highly platform dependent. Connect the child’s controlling terminal to a pseudo-terminal.

What is spawning a shell?

The SPAWN procedure spawns a child process to execute a command or series of commands. Under Windows, a Command Shell is opened. The NOSHELL keyword can be used to execute the specified command directly without starting an intermediate command interpreter shell.

What does the SEND ( ) method do in pexpect?

The string you specify is a regular expression, so you can match complicated patterns. The send () method writes a string to the child application. From the child’s point of view it looks just like someone typed the text from a terminal.

What to do when pexpect does not generate output?

If you wish to read up to the end of the child’s output without generating an EOF exception then use the expect (pexpect.EOF) method. The expect () and read () methods will also timeout if the child does not generate any output for a given amount of time. If this happens they will raise a TIMEOUT exception.

When to expect the EOF in pexpect?

You can also just expect the EOF if you are waiting for all output of a child to finish. For example: If you are trying to optimize for speed then see expect_list (). This is similar to expect (), but uses plain string matching instead of compiled regular expressions in ‘pattern_list’.

How to match the end of a line in pexpect?

Since Pexpect emulates a terminal, to match ends of lines you have to expect the CR/LF combination: If you just need to skip past a new line then expect (‘ ‘) by itself will work, but if you are expecting a specific pattern before the end of line then you need to explicitly look for the .