\typein ¶Synopsis, one of:
\typein{prompt-msg}
\typein[cmd]{prompt-msg}
Print prompt-msg on the terminal and cause LaTeX to stop and wait for you to type a line of input. This line of input ends when you hit the return key.
For example, this
As long as I live I shall never forget \typein{Enter student name:}
coupled with this command line interaction
Enter student name: \@typein=Aphra Behn
gives the output ‘... never forget Aphra Behn’.
The first command version, \typein{prompt-msg}, causes
the input you typed to be processed as if it had been included in the
input file in place of the \typein command.
In the second command version the optional argument cmd
argument must be a command name, that is, it must begin with a
backslash, \. This command name is then defined or redefined to be
the input that you typed. For example, this
\typein[\student]{Enter student name:}
\typeout{Recommendation for \student .}
gives this output on the command line,
Enter student name: \student=John Dee Recommendation for John Dee.
where the user has entered ‘John Dee.’