Thread: how to list contents of a file?

Use the cat command?? When did this become a Unix OS Command board? Sheesh!

Originally posted by zagelle
hi all,

how do i list the contents of a file and calculate the string length (strlen) with it?

thanks!

Open the file.
Read each line.
Add the number of characters read to a counter for the file length
Output the line to list the contents
When done, close the file.

This will work even in Windows and DOS too, whereas the other suggestion is only Unix/Linux.

Quick code

Code:

#include <stdio.h>
#include <stdlib.h>

int main(int argc,char *argv[])
{
  char c;
  FILE *fp;
  if (argc!=2) {
    puts("wrong command.\n");
    exit(1);
  } else
    if ((fp=fopen(argv[1],"r"))!=NULL) {
      while ((c=(char)getc(fp))!=EOF)
        putc(c,stdout);
      fclose(fp);
    } else {
      puts("file not found.\n");
      exit(1);
    }
  return 0;
}

[EDIT] Hoping this is not your homework.

Code:

char c;
while ((c=(char)getc(fp))!=EOF)

FAQ (getc returns an int).

>>(getc returns an int).

You are right.
It's just a quick code. And I only intend to cast it to be printable to stdout. However anybody can fix it.

>And I only intend to cast it to be printable to stdout.

Besides being incorrect for the comparison with EOF, it is also unnecessary -- putc is already performing this conversion.

#include <stdio.h>

int fputc(int c, FILE *stream);
int putc(int c, FILE *stream);

fputc() writes the character c, cast to an unsigned char, to stream.

putc() is equivalent to fputc() except that it may be implemented as a macro which evaluates stream more than once.

Originally posted by Jaguar
Quick code
...

[EDIT] Hoping this is not your homework.

If you are concerned about someone's ability to learn, as you implied, it's best to refrain from posting code that answers the question no matter how easy the solution. I know how it's a kick to be able to answer someone's question, but hold back on the solution so they can learn by solving it.