#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc, char *argv[])
{
    int rdHdl, wr1Hdl, wr2Hdl, i, c;
    char buffer[1024];

    if(argc < 2) {
        printf("Usage: %s <input-filename>\n", argv[0]);
        return -1;
    }

    if((rdHdl = fopen(argv[1], "r")) == -1 ) {
        printf("Error opening file %s.  Error %d:%s\n", argv[1], errno, strerror(errno));
        return -1;
    }

    memset(buffer, 0, sizeof(buffer));
    strncpy(buffer, argv[1], sizeof(buffer));
    strcat(buffer, ".1");

    if((wr1Hdl = fopen(buffer, "w")) == -1 ) {
        // print error
	printf("Error opening file %s for write\n", buffer);
        return -1;
    }

    memset(buffer, 0, sizeof(buffer));
    strncpy(buffer, argv[1], sizeof(buffer));
    strcat(buffer, ".2");

    if((wr2Hdl = fopen(buffer, "w")) == -1 ) {
        // print error
	printf("Error opening file %s for write\n", buffer);
        return -1;
    }

    /* Input file and two output files are now open */
    /* Read input and put into output */

    i=0;
    while(1) {
    	c = fgetc(rdHdl);
    	if( feof(rdHdl) ) 
           break ;
	if(i%2 == 0) { 
	   fputc(c,wr2Hdl);
	} else {
	   fputc(c,wr1Hdl);
	   }
	i++;	

    }

    close(rdHdl);
    close(wr1Hdl);
    close(wr2Hdl);
    // print success
    printf("Completed.\n");
    return 0;
}