Write row by file in a sequence of row

write-row-by-seq.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_ROW_LENGTH 200

void printerr(char* msg) {
	printf("\n%s\n", msg);
	fflush(stdout);
#if defined (__WIN32__)
	system("PAUSE");
#endif
	exit(EXIT_FAILURE);
}

int main(int argc, const char* argv[]) {
	char tablepath[20];
	printf("Insert input table filename: ");
	scanf("%s", tablepath);
	FILE* tablefp = fopen(tablepath, "r");
	if (tablefp==NULL) printerr("Unable to open file.");
	char seqpath[20];
	printf("Insert input sequence filename: ");
	scanf("%s", seqpath);
	FILE* seqfp = fopen(seqpath, "r");
	if (seqfp==NULL) printerr("Unable to open file.");
	char outpath[20];
	printf("Insert output filename: ");
	scanf("%s", outpath);
	FILE* outfp = fopen(outpath, "w");
	if (outfp==NULL) printerr("Unable to open file.");
	
	char** table = malloc(sizeof(char*));
	char* row = malloc(MAX_ROW_LENGTH*sizeof(char));
	int size = 1;
	while (!feof(tablefp)) {
		fgets(row, MAX_ROW_LENGTH*sizeof(char), tablefp);
		if (row==NULL) break;
		table[size-1] = malloc((strlen(row)+1)*sizeof(char));
		if (table[size-1]==NULL) printerr("Error while allocating memory for table.");
		if (row[strlen(row)-1]=='\n') row[strlen(row)-1]='\0';
		strcpy(table[size-1], row);
		char** newtable = realloc(table, (++size)*sizeof(char*));
		if (newtable==NULL) printerr("Error while increasing size memory for table.");
		table = newtable;
	}
	free(row);
	fclose(tablefp);
	
	int n;
	while (!feof(seqfp)) {
		fscanf(seqfp, "%d", &n);
		if (n>0 && n<=size) fprintf(outfp, "%s\n", table[n-1]);
	}
	fclose(seqfp);
	fclose(outfp);
}