LIGTHNING FAST CSV ROW COUNT

csvcount.c

/*
LIGTHNING FAST CSV ROW COUNT
syntax: csvcount filename
niko 2015
*/

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

typedef int bool;
#define true 1
#define false 0

#define BUFSIZE 32768
#define LF 10

int main(int argc, char const *argv[]){
   
   if( argc<2 ){
      printf("syntax %s filename\n", argv[0]);
      return 1;
   }

   FILE *csv = fopen(argv[1], "r");
   if( csv == NULL ){
      printf("error opening %s\n", argv[1]);
      return 2;
   }

   char buf[BUFSIZE];
   bool wasquote = false;
   bool inquote = false;
   long nbrows = 0;
   long n;
   int i, pass = 0;
   char c;

   size_t done = 0;
   fseek(csv, 0L, SEEK_END);
   size_t todo = ftell(csv);
   fseek(csv, 0L, SEEK_SET);

   printf("reading %s (%lu bytes) ...\n", argv[1], todo);

   while( (n = fread(&buf, 1, BUFSIZE, csv)) > 0 ){
      done += n;
      if( todo > 0 && (pass++ % 10) == 0 ) 
         printf(" %d%%\r", (100 * done)/todo);
      for( i = 0; i < n; ++i ){
         c = buf[i];
         if( c == '"' ) {
            if( !inquote && !wasquote ) {
               inquote = true;
            } else {
               if( wasquote ) {
                  wasquote = false;
                  inquote = true;
               } else {
                  wasquote = true;
                  inquote = false;
               }
            }
         } else {
            if( wasquote ) wasquote = false;
            if( !inquote && c == LF ) ++nbrows;
         }
      }
   }

   fclose(csv);
   printf("%lu rows found      \n", nbrows);

   return 0;
}

gcc -o csvcount csvcount.c