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);
}

---

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"

Also, your end-of-file detection won't work correctly. If getc() returns EOF, you first print it to the screen, and then check if you've hit the end of the file. Reverse it: Check first if getc() has returned EOF, then print to screen.

Quote:

---

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");
}

---

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

Quote:

---

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");
}

---

Nah, that's wrong. You want to use fname as an argument to fopen().

--
Mats

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");
}

---

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

Quote:

---

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");
}

---

Close but no cigar:
First of all:

Code:

---

  main(char *fname[] )

---

What the heck is fname doing here? Remove it, leave just empty () like it was in the first few posts.

Are you intending to use command-line arguments? That's not the problem I'm trying to get to towards. And your prompt "Please enter filename" isn't indicating that sort of use.

Second problem is that you have quotes around fname - that means that you are trying to open a file called "fname", not called whatever is in the variable fname that the user entered in the fgets() statement.

And finally, you try to open the file before you've read it's name, so that won't work. Swap some lines about [try to think about what does what, and not just randomly swap lines around - that won't work unless you are lucky, and if you're that lucky, buy a lottery ticket, don't try programming! :-)]

--
Mats

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");
}

---

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

Quote:

---

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

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