Program 8TH in C++

PROBLEM STATEMENT :

You are given a url in a format:
<protocol>://<hostname>:<port>/<filename>
eg. http://www.amazon.com/index.html
implement a function which takes url and do following operations on it:-
1. convert protocol & host name to lowercase.
2. If Url don't contain protocol ,then add http:// at the beginning of the url.
3. replace "//" by "/"
4. if Url contain file name, then remove the file name from the Url.

SOLUTION :

Assumption : The string is entered in proper format.

Character strings can be excluded but if entered, proper syntax is followed.

#include <iostream.h>

#include <cstdio>

#include <string.h>

#include <cstdlib>

using namespace std;

string convertUrl( string s)

{

int i=0;

int j=0;

string protocol="";

//Extracting protocol if present

for(i=0; i < s.length(); i++)

{

if(s[i] == ':')

{

if(s[i+1] == '/' && s[i+2] == '/')

{

protocol=s.substr(0,i+3);

j=i;

i+=3;

break;

}

}

}

//if protocol not present, then j=0, and hence i is set to 0 again.

if( j ==0)

{

i=0;

}

//Changing the case of host name to lower chars if in upper

while( s[i] != '/' && s[i] != '\0' && s[i] != ':')

{

if(s[i] >= 65 && s[i] <= 90)

{

s[i] += 32;

}

i++;

}

//moving from port portin to filename or end of string

if(s[i] == ':')

{

while( s[i] != '/' && s[i] != '\0')

{

i++;

}

}

//at the last slash, if present, filename is extracted out and s is set to string before that only.

if(s[i] == '/')

{

s=s.substr(0,i);

}

//entering protocol if not entered or not correct

if(protocol == "" && protocol != "http://" && protocol != "https://")

{

protocol="http://";

}

// removing one slash from protocol

if(protocol[protocol.length()-1] == '/' && protocol[protocol.length()-2] == '/')

{

protocol[protocol.length()-1]='\0';

}

//Changing protocol part to lower case

for( i=0; i < protocol.length(); i++)

{

if(protocol[i] >=65 && protocol[i]<=90)

{

protocol[i]+=32;

}

}

//merging the two strings on the basis of protocol already present or not

if(j!=0)

{

protocol += s.substr((j+3),s.length());

}

else

{

protocol += s.substr(j,s.length());

}

return protocol;

}

int main()

{

string url;

cout<<"\n\nEnter URL : ";

getline(cin,url,'\n');

cin.clear();

url=convertUrl(url);

cout<<"\n\nThe formatted URL is : "<<url<<endl<<endl;

}