Thread: Help with program

I'm working on a program for school, and its supposed to accept a command line argument to print to a file, but it has to be functional both ways. I cant quite figure out where I'm going wrong it just prints the error statements. Can anyone give me any hints/ideas?
Thanks

Code:

/*Assignment: #1 part #2
    Puropse: Prints ten lines using two nested loops.
    
*/

#include <stdio.h>


main(int argc, char *argv[])
{

/*    FILE *fopen(int argc, char *argv[i]);*/
    FILE *fp;
    int a = 0;
    int b = 0;
    int i;
    
    if (argc < 2)
    {
        fp = fopen(argv[1], "rw+");
        if (!fp)
            printf("Can't open file \n"); 
            else if(argv[1] != '\0')
            {
                while(a < 10)
                {
                    a = 0;
                    ++b;
                    fprint("\n");
                    while(a < b)
                    {
                        fprint("\n");
                        ++a;
                    }
                } 
            }                          
            else if(argv[1] == '\0')
            {
                while(a < 10)
                {                    
                    a = 0;
                    ++b;
                    printf("\n"); 
                    while(a < b)
                    {
                        printf("&#37;d", a);                                   
                       ++a;           
                    }
                }
           }
    }
    
    else (printf("Too many arguments"));
    
    printf("\n");
  
    
}

Using perror() would tell you why the file could not be opened for example.

Code:

        fp = fopen(argv[1], "rw+");
        if (!fp) {
            perror("Can't open file");            
        }

Always use { } to mark the scope of the code to be executed. If you add another statement and forget them, your program will still compile but it won't work as expected.

Misspelling printf as fprint?

[edit]Or the fact that when you enter command line parameter(s), argc oughtta be at least 2? Perhaps...?

Code:

if (argc >= 2)

First off, I wouldn't call your FILE* fprintf. I'm not completely sure if it does anything bad at all, but it's just asking for trouble. Name it something like fp or something.

Then, fprintf, unlike printf, takes 2 or more parameters. The first one is the FILE* to which you want to print, the rest are like any typical printf statement.

Originally Posted by Happy_Reaper

First off, I wouldn't call your FILE* fprintf. I'm not completely sure if it does anything bad at all, but it's just asking for trouble. Name it something like fp or something.

Then, fprintf, unlike printf, takes 2 or more parameters. The first one is the FILE* to which you want to print, the rest are like any typical printf statement.

It is perfectly valid to call a variable the same as a function - as long as you don't use the variable and the function in the same scope - which the above code attempts to do. That will lead to "not a function" error messages.

--
Mats

It is perfectly valid to call a variable the same as a function - as long as you don't use the variable and the function in the same scope - which the above code attempts to do. That will lead to "not a function" error messages.

Right, that's what I was thinking.