03-04-2008
Quote:
Originally Posted by
aforball
Hi Guys,
I've been learning UNIX for the past couple of days and I came across this exercise, I can't get my head around it, so I would be ever so grateful if I could receive some sort of help or direction with this.
Create a file with x amount of lines in it, the content of your choice.
Write a script named 'firstline' that takes two arguments. The first being a line of text, the second being your newly created file. The script should take the first argument and insert it into the very top (the first line) of the file named in your second argument.
Take a copy (backup) and amend the above script so that it now inserts the first argument into the middle of the file.
The problem I have is that I dont know how to edit a text using shell scripts.
Any help would be greatly appreciated
Thanks,
aforball
Learn how to use visual editor or vi. It would surely help you a lot in editing text in shell scripting.
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LEARN(1) General Commands Manual LEARN(1)
NAME
learn - computer aided instruction about UNIX
SYNOPSIS
learn [ -directory ] [ subject [ lesson ] ]
DESCRIPTION
Learn gives Computer Aided Instruction courses and practice in the use of UNIX, the C Shell, and the Berkeley text editors. To get started
simply type learn. If you had used learn before and left your last session without completing a subject, the program will use information
in $HOME/.learnrc to start you up in the same place you left off. Your first time through, learn will ask questions to find out what you
want to do. Some questions may be bypassed by naming a subject, and more yet by naming a lesson. You may enter the lesson as a number
that learn gave you in a previous session. If you do not know the lesson number, you may enter the lesson as a word, and learn will look
for the first lesson containing it. If the lesson is `-', learn prompts for each lesson; this is useful for debugging.
The subject's presently handled are
files
editor
vi
morefiles
macros
eqn
C
There are a few special commands. The command `bye' terminates a learn session and `where' tells you of your progress, with `where m'
telling you more. The command `again' re-displays the text of the lesson and `again lesson' lets you review lesson. There is no way for
learn to tell you the answers it expects in English, however, the command `hint' prints the last part of the lesson script used to evaluate
a response, while `hint m' prints the whole lesson script. This is useful for debugging lessons and might possibly give you an idea about
what it expects.
The -directory option allows one to exercise a script in a nonstandard place.
FILES
/usr/share/learn subtree for all dependent directories and files
/usr/tmp/pl* playpen directories
$HOME/.learnrc startup information
SEE ALSO
csh(1), ex(1)
B. W. Kernighan and M. E. Lesk, LEARN - Computer-Aided Instruction on UNIX
BUGS
The main strength of learn, that it asks the student to use the real UNIX, also makes possible baffling mistakes. It is helpful, espe-
cially for nonprogrammers, to have a UNIX initiate near at hand during the first sessions.
Occasionally lessons are incorrect, sometimes because the local version of a command operates in a non-standard way. Occasionally a lesson
script does not recognize all the different correct responses, in which case the `hint' command may be useful. Such lessons may be skipped
with the `skip' command, but it takes some sophistication to recognize the situation.
To find a lesson given as a word, learn does a simple fgrep(1) through the lessons. It is unclear whether this sort of subject indexing is
better than none.
Spawning a new shell is required for each of many user and internal functions.
The `vi' lessons are provided separately from the others. To use them see your system administrator.
7th Edition October 22, 1996 LEARN(1)