c - Segmentation fault in program using command line arguments -

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i'm trying write program finds largest , smallest of 10 numbers.

to use program, must use command line argument -l numbers determine largest number, same command -s smallest numbers.

however, when don't enter command @ all, , try run program, receive segmentation fault. not sure went wrong.

#include <stdio.h> #include <stdlib.h> #include <string.h>  int main(int argc, char* argv[]) {     int i;     int min,max,num;     char *argv1 = argv[1];     char *small = "-s";     char *large = "-l";     min=max=0;     if (0==strcmp(argv1, small))     {          (i=2; i<argc; i++)         {             num=atoi(argv[i]);             if(i==2)             {                 min=num;             }             else             {                 if(min>num)min=num;             }         }     printf("the smallest number %d\n",min);     }     else if (0==strcmp(argv1, large))     {          (i=2; i<argc; i++)     {         num=atoi(argv[i]);         if(i==2)         {             max=num;         }         else         {             if(max<num)max=num;         }     }     printf("the largest number %d\n",max);     }     else     {         printf("invalid option");     } return 0; }

check number of arguments before accessing arguments.

int main(int argc, char* argv[]) {     int i;     int min,max,num;     char *argv1 = argv[1];     char *small = "-s";     char *large = "-l";     /* add here */     if(argc < 2)     {         fprintf(stderr, "usage: %s command numbers...\n", argc > 0 ? argv[0] : "");         return 1;     }     /* add until here */     min=max=0;

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