#include <stdio.h>
#include <assert.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc, char** argv) {
	int i;
	FILE* fp;
	FILE* pipep;
	int count = 0;
	char* command;
	int lines;
	float* data;
	int j;
	char* target;
	int fd;

	if ( argc < 2 ) {
		fprintf(stderr, "Usage %s files-to-check\n", argv[0]);
		return -1;
	}

	for ( i = 1; i < argc; i++ ) {
		fp = fopen(argv[i],"r");
		if ( fp != 0 ) {
			/* figure out how many lines */
			command = (char*)malloc(8+strlen(argv[i]));
			sprintf(command, "wc -l %s", argv[i]);
			pipep = popen(command, "r");
			free(command);
			fscanf(pipep, "%d", &lines);
			pclose(pipep);
			data = (float*)malloc(lines*2*sizeof(float));
			for ( j = 0, count = 0; ; count++ ) {
				if ( fscanf(fp, "%f,%f", &data[j], &data[j+1])  != EOF ) {
					j += 2;
				} else {
					break;
				}
			}
			assert(count == lines);
			fclose(fp);
			target = strstr(argv[i],".csv");
			strcpy(target, ".dat");
			fd = open(argv[i], O_WRONLY | O_CREAT,
				S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
			count = write(fd, data, lines*2*sizeof(float));
			assert(count == lines*2*sizeof(float));
			close(fd);
			free(data);
		} else {
			fprintf(stderr, "%s: Can't open %s\n", argv[0], argv[i]);
			return -2;
		}
		fclose(fp);
	}

	return 0;
}