C Errors (Beginner)

Question

#include <stdio.h>

main(void) {
file *file = fopen("words.txt","r") 
if(file != null) {
    char line[128];
    while(fgets( line, sizeof line, file) != null) 
    {
    fputs ( line, stdout );
    }
    fclose ( file );
    }
}

This is my code. im trying to read a file, and output the content. but this gives me error codes

main.c: In function 'main':
main.c:4: error: 'file' undeclared (first use in this function)
main.c:4: error: (Each undeclared identifier is reported only once
main.c:4: error: for each function it appears in.)
main.c:5: error: parse error before "if"
main.c:7: error: 'line' undeclared (first use in this function)
main.c:7: error: 'null' undeclared (first use in this function)
main.c: At top level:
main.c:13: error: parse error before '}' token
main.c:13:2 warning: no newline at end of file

how do i fixs this errors.

Answer 1

Try capitalizing FILE.

Answer 2

• File should be capitalized at the begininning of line 4
• the end of line 4 is missing a semicolon, leading to the parse problem on line 5

EDITED twice, because I was wrong on the edit. oops.

Answer 3

FILE and NULL are wrongly written (C is case sensitive). fopen line was missing a semicolon.

Code below compiles and runs.

#include <stdio.h>

main(void) {
FILE *file = fopen("words.txt","r"); 
if(file != NULL) {
    char line[128];
    while(fgets( line, sizeof line, file) != NULL) 
    {
    fputs ( line, stdout );
    }
    fclose ( file );
    }
}

Answer 4

The file type is defined in stdio.h and must be all-caps (FILE). Simple mistake to make.

Answer 5

In addition to the other things already pointed out, your main() function should be specified as returning an int and should explicitly do so at the end. Also, I don't quite understand your indentation and bracketing style.

#include <stdio.h>

int main(void)
{
  FILE *file = fopen("words.txt","r"); 
  if(file != NULL)
  {
    char line[128];
    while(fgets( line, sizeof line, file) != NULL) 
    {
      fputs ( line, stdout );
    }
    fclose ( file );
  }
  return 0;
}

Alternatively, you could make it return 1; (error codes are usually non-zero on UNIX) if the file doesn't open:

#include <stdio.h>

int main(void)
{
  FILE *file = fopen("words.txt","r"); 
  if(file != NULL)
  {
    char line[128];
    while(fgets( line, sizeof line, file) != NULL) 
    {
      fputs ( line, stdout );
    }
    fclose ( file );
    return 0;
  }
  else
  {
    return 1;
  }
}

Answer 6

The following works fine and has been cleaned up with consistent braces and spaces in function calls and definitions and loops/ifs. It also works in C, if that was your intent from the tags, and prints an error and returns 1 if the file cannot be opened.

#include <stdio.h>
#include <errno.h>

int main (void) {
    char line[128];
    FILE *file = fopen ("words.txt", "r");
    if (file != NULL) {
        while (fgets (line, sizeof line, file) != NULL) {
            fputs (line, stdout);
        }
        fclose (file);
    } else {
        fprintf (stderr, "Cannot open 'words.txt', error = %d\n", errno);
        return 1;
    }
    return 0;
}