ex4_readline.c File Reference

Appfs Example: line wise text input. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>

Go to the source code of this file.

Macros
#define	MAX_LINE_LEN   512

Functions
int	process_file (const char *filename)
	Read a textfile, remove comments and process lines. More...
int	main (int argc, char **argv)

Detailed Description

Author

Thorsten Koch

Date

07Nov2014

gcc -O2 -Wall -o ex4_readline ex4_readline.c

Using fgets() for input

Definition in file ex4_readline.c.

Macro Definition Documentation

#define MAX_LINE_LEN   512

Definition at line 16 of file ex4_readline.c.

Function Documentation

int main	(	int	argc,
		char **	argv
	)

Definition at line 64 of file ex4_readline.c.

{
   if (argc < 2 || strlen(argv[1]) <= 0)
   {
      fprintf(stderr, "usage: %s filename", argv[0]);
      return EXIT_FAILURE;
   }
   printf("%d lines\n", process_file(argv[1]));
   
   return EXIT_SUCCESS;
}

int process_file

(

const char *

filename

)

Parameters

filename

name of file to read

Returns

number of lines read

Definition at line 22 of file ex4_readline.c.

{
   assert(NULL != filename);
   assert(0    <  strlen(filename));

   FILE* fp;
   char  buf[MAX_LINE_LEN];
   char* s;
   int   lines = 0;
   
   if (NULL == (fp = fopen(filename, "r")))
   {
      fprintf(stderr, "Can't open file %s\n", filename);
      return -1;
   }
   while(NULL != (s = fgets(buf, sizeof(buf), fp)))
   {
      char* t = strpbrk(s, "#\n\r");

      lines++;
      
      if (NULL != t) /* else line is not terminated or too long */
         *t = '\0';  /* clip comment or newline */
      
      /* Skip over leading space
       */
      while(isspace(*s))
         s++;

      /* Skip over empty lines
       */
      if (!*s)  /* <=> (*s == '\0') */
         continue;

      /* do processing here
       */
   }
   fclose(fp);

   return lines;
}