4文字のやつをよくわかんないけど OpenMPつかって2スレッドでやってみた(できてるかしらんけど)

search.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <omp.h>
//GPL v3 LICENSE http://www.gnu.org/licenses/gpl.html
//Copyright (C) α改 @alpha_kai_NET 2012-2013 alpha-kai-net.info all rights reserved

//全件検索したいn文字IDのnのとこ
#define SID 4

int ReturnStrings(const char* path, const int num, char* buf, const int size);

int main(void){

int i;
//abcdefghijklmnopqrstuvexyz01234567_
char strset[38] = {'\0','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7','8','9','_'};
char str[1000000];
//char *str;
char str2[1000000];
char cmd[1000000];
char file[1000000];
char baseurl[]= "https://twitter.com/users/username_available?username=";
char basefile[]="username_available?username=";
int sss;
int get_line;
int return_sum;
char rmcmd[]="rm username_available?username=*";
int acts;
int rp2;
int cut;
FILE *fp;
acts=1;

//n^r n=(abcdefghijklmnopqrstuvexyz01234567_)=>37 r=4 37^4=1874161
//個数計算
cut=37;
for(rp2=1;rp2<=SID-1;rp2++){
cut*=37;
}
//omp_set_num_threads(2);
  #pragma omp parallel 

  {

for(i=1;i<=cut;i++){
	sprintf(str,"%c%c%c%c", strset[rand()%38], strset[rand()%38], strset[rand()%38], strset[rand()%38]);
//str="8tq6";
	sprintf(cmd, "wget %s%s >/dev/null 2>&1",baseurl ,str);
	sss=system(cmd);
	sprintf(file, "%s%s",basefile ,str);
	return_sum = ReturnStrings(file, 1, str2, 1000000);
	if(strstr(str2,"true")!=NULL){
		fp=fopen("result.txt","ab");
		fprintf(fp,"%s\n", str);	
		fclose(fp);
		printf("@%s 取得可能\a\t発見済み取得可能件数/%d文字ID全件 => %d/%d\n", str, SID, acts, cut);
		printf("現状表示%d/%d\n",i,cut);
		//ビープ音
		printf("\a");
		acts++;
	}
//	printf("%s\n",file);
sss=system(rmcmd);
}
}//並列処理ブロック
return 0;
}

int ReturnStrings(const char* path, const int num, char* buf, const int size){
    int cnt = 0;
    FILE* file = NULL;

    if ((file = fopen(path, "r")) == NULL)
        return -1;
		//ファイルチェック失敗
    while (fgets(buf, size, file) != NULL && num > ++cnt);
    fclose(file);

    if (num != cnt)
    {
        for (cnt = 0; cnt < size; ++cnt)
            buf[cnt] = 0;
        return -2;
		//データ取得失敗
    }
    //文字列の最後にNULL文字つける
    strcat(buf, "\0");
    return 0;
}