file merger

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November 15th, 2002, 04:19 AM

empty

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file merger

Im writing a file merger mainly for concating phrack issues =P - but it compiles and doesnt wanna open files and keeps crashing =\ quite odd - if anyone can help would be appriecated - here is the code :

PHP Code:


		
			
#include <stdio.h>

#include <stdlib.h>

#include <string.h>



void readstdin(char *array, char *strbuff);



int main()

{

   int i, c2;

   char c = 'y';

   char *base;

   char *filem;

   char *strbuff = ( char* ) calloc( 1024, sizeof(char) );

   FILE *fp1;

   FILE *fp2;



   printf("Choose base file ?\n>>");

   readstdin(base, strbuff);

   free( strbuff );

   fp1 = fopen(base, "a+");

   while( !fp1 ) {

         printf("- failed opening file -\n");

         printf("Choose base file ?\n>>");

         readstdin(base, strbuff);

         free( strbuff );

         fp1 = fopen(base, "a");

   }



   while( c != 'n' ) {

      printf("Choose file to merge ?\n>>");

      readstdin(filem, strbuff);

      free( strbuff );

      fp2 = fopen(filem, "rb");

      while( !fp2 ) {

         printf("- failed opening file -\n");

         printf("Choose file to merge ?\n>>");

         readstdin(filem, strbuff);

         free( strbuff );

         fp2 = fopen(filem, "rb");

      }



      while( (c2 = fgetc(fp2)) != EOF ) {

         fputc(c2, fp1);

      }

      fclose(fp2);



      printf("\nWould you like to merge a file ?");

      scanf("%c", c );

   }

   fclose(fp1);



   system("pause");

  return 0;

}



void readstdin(char *array, char *strbuff)

{

   scanf( "%s", strbuff );

   array = ( char* ) calloc( strlen(strbuff), sizeof(char) );

   strcpy( array, strbuff );

}

NB: used PHP tags but its C

November 15th, 2002, 04:47 AM

matj222

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Location: australia

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HI ALEN

Well i would help u if u werent such a newb
how found da best book on python, it called "core python programming"
heard of it??

November 15th, 2002, 12:17 PM

M.Hirsch

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Posts: 5,966

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Reputation Power: 189

one problem i can see at the first glance:

PHP Code:


		
			
 void readstdin(char *array, char *strbuff)

...

   array = ( char* ) calloc( strlen(strbuff), sizeof(char) );

you assign to the char*, but this makes "array" a local copy (!) in the scope of "readstdin()".

you need to pass a pointer to the pointer or a reference to the pointer.
eg.

PHP Code:


		
			
 void readstdin(char **array, char *strbuff)

{

   scanf( "%s", strbuff );

   *array = ( char* ) calloc( strlen(strbuff), sizeof(char) );

   strcpy( array, strbuff );

}

or you can allocate the memory in the main function instead before calling readstdin()

__________________
--
Manuel Hirsch - Linux, FreeBSD, programming, administration articles, tutorials and more.

November 15th, 2002, 07:41 PM

empty

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Location: Australia

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hmm - I tried that but same thing: it gets the base file now and crashes when opening the file to be appended.
Plus one minute Dev-C++4 was throwing an error -

d:\my documents\projects\untitled1.c: In function `main':
d:\my documents\projects\untitled1.c:18: warning: passing arg 1 of `readstdin' from incompatible pointer type
d:\my documents\projects\untitled1.c:25: warning: passing arg 1 of `readstdin' from incompatible pointer type
d:\my documents\projects\untitled1.c:32: warning: passing arg 1 of `readstdin' from incompatible pointer type
d:\my documents\projects\untitled1.c:39: warning: passing arg 1 of `readstdin' from incompatible pointer type
d:\my documents\projects\untitled1.c: In function `readstdin':
d:\my documents\projects\untitled1.c:62: warning: passing arg 1 of `strcpy' from incompatible pointer type

- then iI compile again and it does, very odd.
Also wondering if that is a problem why doesnt Dev-C++ catch it ?

Last edited by empty : November 15th, 2002 at 07:46 PM.

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