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Top Forums Programming Insert Text at begining of file Post 302199504 by netwolf on Tuesday 27th of May 2008 04:01:56 AM
Old 05-27-2008
Question Insert Text at begining of file

Hi All,

Its been a long time since i did any programming and I am trying to get back into it as part of also learning Linux. Coming from a Cpp background i am trying to write some simple code just using C.

I want to create a simple log file but instead of appending to the end of the file i want to prepend it at the start. Try as i might i cant find any references to prepending text to a file.

I have tried rewind and fprintf to get to the top of the file but it overwrites existing entries at the top. How can i insert the text. Secondly I have read it is better for portability to use the Low Level I/O functions like open() read(), write and creat(). Can some one give me an example using the buffered methods like fopen, fprintf streams and the unbuffered methods like open() write() etc. I have read that fopen actually calls open() to open the file but provides a buffered stream.

I would appreciate your help very much. The books i have dont seem to go into much detail and though I have found many examples of reading and writing they dont seem to cover how to prepend. I suppose i could create a new file, but this seems to be a long way around the problem.

Thanks in advance and Regards
 

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Pod::Text::Termcap(3pm) 				 Perl Programmers Reference Guide				   Pod::Text::Termcap(3pm)

NAME
Pod::Text::Termcap - Convert POD data to ASCII text with format escapes SYNOPSIS
use Pod::Text::Termcap; my $parser = Pod::Text::Termcap->new (sentence => 0, width => 78); # Read POD from STDIN and write to STDOUT. $parser->parse_from_filehandle; # Read POD from file.pod and write to file.txt. $parser->parse_from_file ('file.pod', 'file.txt'); DESCRIPTION
Pod::Text::Termcap is a simple subclass of Pod::Text that highlights output text using the correct termcap escape sequences for the current terminal. Apart from the format codes, it in all ways functions like Pod::Text. See Pod::Text for details and available options. NOTES
This module uses Term::Cap to retrieve the formatting escape sequences for the current terminal, and falls back on the ECMA-48 (the same in this regard as ANSI X3.64 and ISO 6429, the escape codes also used by DEC VT100 terminals) if the bold, underline, and reset codes aren't set in the termcap information. SEE ALSO
Pod::Text, Pod::Simple, Term::Cap The current version of this module is always available from its web site at <http://www.eyrie.org/~eagle/software/podlators/>. It is also part of the Perl core distribution as of 5.6.0. AUTHOR
Russ Allbery <rra@stanford.edu>. COPYRIGHT AND LICENSE
Copyright 1999, 2001, 2002, 2004, 2006, 2008, 2009 Russ Allbery <rra@stanford.edu>. This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself. perl v5.16.2 2012-08-26 Pod::Text::Termcap(3pm)
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