Puppy Linux Discussion Forum

[Cur Dog]

Can someone help point me to a guide that would help me to write a script that would either combine two text files or add lines of text from within the script file itself to an existing text file.

Thanks,
Cur Dog

[Bruce B]

combining two text files is usually appending one to another.

say we want to append file2.txt to file1.txt

# cat file2.txt >>file1.txt

if you planned to do the same action over and over then the line in the script read the same way.

if you only use one > you will clobber file1.txt, so be advised

if we want a script to append it's a wonderful day to a file it could like this:

[Cur Dog]

OK, I must be missing something......This is what I used.

[Juveno41]

Some programs seem to need special variables or lines set in a system file.

Let's say, we have to add a line in the file '/root/.xinitrc' after installing a PET package.

for example :

export VARIABLE_NAME="VARIABLE_VALUE"


then you can't just append a line to '/root/.xinitrc',as it would cause some problems.


How do people handle this?

Should this be done with a script? If so, can someone tell me where I can see some examples, please.

Or is it better not to mess up with system files in this manner...

[Pizzasgood]

You mis-read his example. It was supposed to be used exactly, with no modifications. The part you changed was to tell the user they were suppposed to call the program with a parameter:
thescriptsname "/root/blah.txt"
Then, it would append "it's a wonderful day" to the file /root/blah.txt.

This will append "eat more cheese" to /tmp/todolist:
echo "eat more cheese" >> /tmp/todolist

This will append the contents of /tmp/stuff to /tmp/bob
cat /tmp/stuff >> /tmp/bob

Basically, if you put >> /tmp/file after any command, that command's normal output will be appended to /tmp/file. You can append the error output like this:
2>> /tmp/file
You can append both normal and error output to /tmp/file like this:
>>/tmp/file 2>&1

The echo command simply outputs it's input, which is why you can use it to output specific things, or the contents of a specific variable:
echo $MYVAR >> /tmp/stuff

The cat command displays the content of the file you use it on. cat /tmp/stuff just displays the contents of /tmp/stuff. Then adding the >> /tmp/bob appends that output to /tmp/bob.

[Cur Dog]

Well I guess I am having problems seeing the forest because of all of the trees. I still can't get the example to work. If I use the cat command in the script, it appends one file to the other. This is actually the way that I believe benefits me the most. However, I still would like to understand what I am doing wrong. I have saved the example as first.sh. If I execute it nothing happens. I have called it from within another script

[Bruce B]

[Cur Dog]

I would like to say THANK YOU to both Bruce and Pizzasgood. It was the missing space that was causing my problem. That can make one feel really stupid.

Cur Dog

[Bruce B]

Stupid is giving up. Intelligence is recognizing when you need help and you get help.

I'll recommend Steve Parker's Tutorial as a good one to get started with if you want to learn more about bash scripting.

[Cur Dog]

Thanks, I will be sure to check it out.
Again, I thank you for your help.

Cur Dog