popen()

 1 /*============================================
 2 > Copyright (C) 2014 All rights reserved.
 3 > FileName：my_ponen.c
 4 > author：donald
 5 > details：
 6 ==============================================*/
 7 #include <unistd.h>
 8 #include <stdio.h>
 9 #include <stdlib.h>
10 #include <string.h>
11 int main(int argc, const char *argv[])
12 {
13 int left,right,sum;
14 FILE* fp ;
15 char cmd[1024] = "";
16 while(1){
17 scanf("%d%d",&left,&right);
18 sprintf(cmd,"%s %d %d",argv[1],left,right);
19 fp = popen(cmd,"r");
20 fscanf(fp,"%d",&sum);
21 printf("result is : %d\n",sum);
22 
23 pclose(fp);
24 }
25 return 0;
26 }

 1 /*============================================
 2   > Copyright (C) 2014 All rights reserved.
 3   > FileName：mystring.c
 4   > author：donald
 5   > details：
 6 ==============================================*/
 7 #include <stdio.h>
 8 #include <stdlib.h>
 9 #include <string.h>
10 #define N 1024
11 int main(int argc, const char *argv[])
12 {
13     int index;
14     char buf[N];
15     memset(buf,0,N);
16     for(index = argc - 1;index > 0;index --){
17         strcat(buf,argv[index]);
18         strcat(buf," ");
19     }
20     printf("%s\n",buf);
21     return 0;
22 }