Thread: file handling functions

When I try to run this program it says "File doesn't exist" but the file dose exist under C:\ can someone help please.

Code:

  #include "stdio.h"
   main( )
   {
     FILE *text;
     char c;
     text = fopen("C:\text.txt", "r");
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       c = getc(text); /* get one character from the file
       */
         putchar(c); /* display it on the monitor
       */
       } while (c != EOF); /* repeat until EOF (end of file)
     */
     }
    fclose(text);
}

Originally Posted by Cactus_Hugger

Code:

Not:
"C:\text.txt"
Use:
"C:\\text.txt"

backslash is the escape character, and starts escape sequences. \t, specifically, is a tab. You're trying to open "C: ext.txt"

Ah ha ok thanks Cactus_Hugger that fixed it

How would I make the below code so the file is found and printed out on the monitor by user input.

Thanks

Code:

#include <stdio.h>
#include <stdlib.h>
   main( )
   {
     FILE *text;
     char c;
     printf("Please enter file name to open:\n");
     text = fopen("C:\\text.txt", "r");
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       c = getc(text); /* get one character from the file
       */
         putchar(c); /* display it on the monitor
       */
       } while (c != EOF); /* repeat until EOF (end of file)
     */
     }

    fclose(text);
    system("PAUSE");
}

Originally Posted by matsp

add something like:

Code:

#include <stdlib.h>
...
int main(...)
{
...
    char fname[MAX_PATH];
...
    fgets(fname, sizeof(fname), stdin);

Now replace your constant with fname, and all should work.

--
Mats

Hey matsp ok thanks again I will give it a go

Cheers

OK I this code and get the following errors

Code:

12 c:\mjm7ss~1.cpp incompatible types in assignment of `int' to `char[260]'
14 c:\mjm7ss~1.cpp passing `char *' to argument 1 of `putchar(int)' lacks a cast
16 c:\mjm7ss~1.cpp ANSI C++ forbids comparison between pointer and integer

Code:

#include <stdio.h>
#include <stdlib.h>
   main( )
   {
     FILE *text;
     char fname[MAX_PATH];
     printf("Please enter file name to open:\n");
     fgets(fname, sizeof(fname), stdin);
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       fname = getc(text); /* get one character from the file
       */
         putchar(fname); /* display it on the monitor
       */
       } while (fname != EOF); /* repeat until EOF (end of file)
     */
     }

    fclose(text);
    system("PAUSE");
}

Is this getting close LOL

Code:

#include <stdio.h>
#include <stdlib.h>
   main(char *fname[] )
   {
     FILE *text;
     char c;
     char fname[MAX_PATH];
     printf("Please enter file name to open:\n");
     fgets(fname, sizeof(fname), stdin);
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       c = getc(text); /* get one character from the file
       */
         putchar(c); /* display it on the monitor
       */
       } while (c != EOF); /* repeat until EOF (end of file)
     */
     }

    fclose(text);
    system("PAUSE");
}

Originally Posted by matsp

You need to get this line:

Code:

     text = fopen("C:\\text.txt", "r");

back in, but replace your "C:\\text.txt" with fname.

[I am being kind today, am I not :-)]

--
Mats

Yes and very patient ok so now i have this but am getting error '7 c:\mjm7ss~1.cpp
declaration of `fname' shadows a parameter'

Code:

#include <stdio.h>
#include <stdlib.h>
   main(char *fname[] )
   {
     FILE *text;
     char c;
     char fname[MAX_PATH];
     printf("Please enter file name to open:\n");
     text = fopen("fname", "r");
     fgets(fname, sizeof(fname), stdin);
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       c = getc(text); /* get one character from the file
       */
         putchar(c); /* display it on the monitor
       */
       } while (c != EOF); /* repeat until EOF (end of file)
     */
     }

    fclose(text);
    system("PAUSE");
}

I am starting to go nuts... Maybe I should go buy a lottery ticket

Code:

#include <stdio.h>
#include <stdlib.h>
   main( )
   {
     FILE *text;
     char c;
     char fname[MAX_PATH];
     printf("Please enter file name to open:\n");
     fgets(fname, sizeof(fname), stdin);
     text = fopen(fname, "r");
     if (text == NULL) printf("File doesn't exist\n");
     else {
      do {
       c = getc(text); /* get one character from the file
       */
         putchar(c); /* display it on the monitor
       */
       } while (c != EOF); /* repeat until EOF (end of file)
     */
     }

    fclose(text);
    system("PAUSE");
}

Originally Posted by matsp

Sorry, yes, fgets() includes the newline in the line of text. If you add this between fgets() and fopen(), it should fix it up:

Code:

if (fname[strlen(fname)-1] == '\n') fname[strlen(fname)-1] = 0;

Sorry about that.

--
Mats

Hey No problem I am very grateful for all the help you guys have been giving me, It works now thanks.