[GAP Forum] question about strings

[Frank Heckenbach]

Justin C. Walker wrote:

> On May 24, 2007, at 08:47 , Joao Araujo wrote:
> 
> > 1. the original files are very very big. It might take hours to  
> > reach the end of the file using the scroll of nano or pico. So I  
> > have been transfering the files to a Windows machine and use a word  
> > processor to
> > reach the end (and put ";; ). Then send the file back to the unix  
> > machine.
> 
> Sheesh...you're working pretty hard to get these two characters in  
> there...
> 
> Your best bet is to write a small C program to do the job:
>     main(...)
>     {
>        fd = open(...);
>        lseek(fd, 0, SEEK_END);
>        write(fd, ";;\n", 3);
>     }
> 
> That, obviously, has not been compiled or tested :-}, nor is there  
> any error-checking.  It will beat the pants off the "scroll to the  
> end and type ';;'" process, though.
>
> There may even be Perl or Pythonic ways of doing the same thing.   
> Look for "seek" or "append" methods in these scripting languages.  In  
> essence, you want to seek to the end of the file, write the two  
> characters there, and close the file.

Though a bit OT here, the simplest way in Unix requires neither C,
Perl, Python nor a text editor. The shell with its built-in "echo"
command does it just fine (and very quickly):

echo -n ";;" >> filename

Frank Heckenbach

-- 
Frank Heckenbach, heckenb at mi.uni-erlangen.de
http://www.mi.uni-erlangen.de/~heckenb/
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