NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part2/10244

Internet Message Format | 1996-08-05 | 2.5 KB

Path: news.unt.edu!news
From: Steve Fogoros <[e-mail]>
Newsgroups: comp.lang.c
Subject: Re: ?? How to dump text files to screen ??
Date: Fri, 15 Mar 1996 23:42:55 -0800
Organization: University of North Texas Health Science Center
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Tristan Psionic wrote:
TP>
TP> In <[e-mail]>, Neil <[e-mail]> writes:
TP> >I need help -- how can I open up a text file and just dump it
TP> >all out (in plain text) to the screen?
TP> Well, you can't do exactly that, but this is pretty close (and pretty raw):
TP>
TP> #include <stdio.h>
TP>
TP> void main (int argc,char argv[])

I have been reminded a number of times that main returns int and should be declared as
such. I agree in that script error level checking depends on main returning something to
indicate sucess or failure. I don't yet know if this is required by ANSI C. I have been
declaring main as returning void because I call exit() to end a program on both failure
and sucess. If I don't declare it void I get a compiler warning that the function should
return a value. Since main is not the function that sets the program return value, I
don't see why I should put in a return at the end of main just so I can declare it as
returning int. In this case, since the program ends at main you should declare it
returning int and return something.

Also, argv[] should be *argv[] or **argv

TP> {
TP>   FILE *fp;
TP>   char s[1000];

For my example, drop the array and add,

int c;

TP>   if (argc >= 1)
TP>   {
TP>     fp=fopen(argv[1],"r");

Test fp before using it. If it is equal to NULL you have a failure opening the file.

if(fp == NULL) return 10;

TP>     while (gets(s,1000,fp) != NULL)
TP>     {
TP>       printf("%s",s);
TP>     }

Instead of taking a chance that the input string is longer than 1000 chars, you can read
and output a character at a time.

while((c = getc(fp)) != EOF)
   putc(c,stdout);

TP>     fclose(fp);
TP>   }
TP>   else
TP>   {
TP>     printf("usage:  dumptext [filename]"
TP>   }

return 0;

TP> }
TP>
TP> That should work.  I'm not an expert at C or anything, but I do believe that
TP> there aren't any hugely flawed errors in it.  Good luck.
TP> -tristan

--
Steve Fogoros, Academic Information Coordinator
University of North Texas Health Science Center
[e-mail]