Copying a Specific Line from a File

[garrensilverwing]

Hi again guys!

I have something I am failing at figuring out. I want to write some code to copy the entire line of a particular file so that I can move it to another file. However, I do not know how to copy the line of the file. I know exactly which line it will be 100% of the time I just can't find anything on google to help me.

Thanks again!

[4xware]

It depends on the programming language.
For example, in PHP you can try the file() function.

[siremethmimetes]

Greetings,

It depends on where you are and what you can use. I know how to do it real easy with perl, but that might not be available to you. I am pretty sure the Shell can as well. But that would take skills beyond my current ken.

With joy and peace in Christ,
Sir Emeth Mimetes

[ah-blabla]

You probably have to read through all the lines beforehand first before you can read the line you want. Alternatively you can use a random access file object (I know there's something like this for java), but they are completely unaware of lines, so you need to know from exactly which byte you want to read.

[descalzo]

1. Which language? The two most applicable are PHP and Perl if you are talking about a web script.
2. When you say you know 'which line' it is, is it by number or by some specific content?
3. Do you want to just copy the line, or do you want to remove it from the original file?
4. Do you want to just add the line to the destination file, overwriting what is there, or do you want to add it to the end, etc?
Add:
5. Local file or a web page?

[garrensilverwing]

sorry i forgot to mention i'm using php, im not too versed with perl

[liketobemad]

For PHP
it is very simple load contents into a array by file.. and append to the destination
Have a look here
http://www.w3schools.com/PHP/php_file.asp
or go to
http://php.net
and have a look for file() function

[descalzo]

$all_lines = file( "PATH_TO_THE_FILE_WITH_THE_LINE"); 
 
# NOTE: NUMBERING STARTS AT 0, NOT 1
 
$the_line = $all_lines[ "NUMBER_OF_YOUR_LINE"];  
 
 # ERASES ANYTHING IN THE FILE AND JUST WRITES THE LINE 
 
file_put_contents( "PATH_TO_DESTINATION_FILE" , $the_line  ); 
 
# IF YOU WANT TO ADD IT TO THE END OF A FILE... 
 
file_put_contents( "PATH_TO_DESTINATION_FILE" , $the_line , FILE_APPEND ); 

[garrensilverwing]

Ahhh thanks a lot descalzo, i got it to work how i wanted!