Thread: location of a substring in a string

Hello,i have this program to search a sub string in string and tells its location but it is only telling the position of first matched character.help me if u can.

Code:

#include<stdio.h>
#include<conio.h>
#include<string.h>
int searchsubstring(char *,char *);
int position (char *,char*);


int main()
{
char s1[10],s2[10];
int i,v,j,f=0;
printf("Enter main string : ");
gets(s1);
printf("Enter substring to be searched in main string : ");
gets(s2);
if(searchsubstring(s1,s2)!=0)
printf("\nFound");
else
printf("\nNot found");
v=position(s1,s2);

printf ("\nLocation of substring: %d",v);
}

int searchsubstring(char *s1,char *s2)
{
int f=0;
for(;*s1!='\0';)
{
if(*s2=='\0')
break;
for(;*s2!='\0';)
{
if(*s1==*s2)
{
f=1;
s1++;
s2++;
}
else
{
f=0;
s1++;
break;
}
}
}
if(f==0)
return 0;
else
return 1;
getch();
}

int position(char *s1,char *s2)
{
int f=0,x=0;
for(;*s1!='\0';)
{
if(*s2=='\0')
break;
for(;*s2!='\0';)
{
if(*s1==*s2)

{
f=1;
s1++;
s2++;
x++;
return x;
}
else
{
f=0;
s1++;
x++;
break;
}
}
}
}

You STILL need to indent your code - that's a mess to have to study.

You WANT to search "on your own", instead of using strstr() which is made for this?

In your search loop, you need to move the position of the pointer (file pointer, or index), to the next char, and continue looping until you reach the end of the string (or get close enough that the substring you're searching for, is larger than the remaining letters in the string you're looking through).