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how can i parse part of string ? (urgent)

Posted on 2004-09-19
Medium Priority
Last Modified: 2010-04-01
Hi experts,

I have a string, like " this is a customer account, ref: abc#123456789 ".
I only need to parse partial string "ref: abc#123456789". how can i do that ?
Any function can do that ?

Question by:justinY
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LVL 86

Accepted Solution

jkr earned 500 total points
ID: 12097318
You'd find the start of the substring by e.g. looking for 'ref:', like

char acSomeString[] = " this is a customer account, ref: abc#123456789 ";

char* pszStringToParse = strstr ( acSomeString, "ref:");

// will then be "ref: abc#123456789 "

Expert Comment

ID: 12098959
try this:

#include <iostream>

using namespace std;

char* FindSubStr ( char *str, int size, char *query )
      int IndexOfSubStr = 0;

      // find occurence of substr
      for ( int i = 0; i < size; i++ )
            if ( str[i] == query[0] && str[i+1] == query[1] && str[i+2] == query[2] )
                  IndexOfSubStr = i;

      static char substr[128];
      int substrIndex = 0;
      // copy string to substr and return it
      for ( i = IndexOfSubStr; i < size; i++ )
            substr[substrIndex] = str[i];

      return substr;
int main ()
      // input string
      char str[128] = "this is a customer account, ref: abc#123456789";
      // substr stores the sub string if found
      char *substr;
      // size of input string
      int size = strlen ( str );

      // call function to find our string
      substr = FindSubStr ( str, size, "ref:" );

      cout << substr << endl;

      return 0;
LVL 10

Expert Comment

ID: 12099065
More C++ way of doing it

#include <iostream>
#include <string>

using namespace std ;
int main () {

      string s1 = "this is a customer account, ref: abc#123456789 ";

      unsigned int pos = s1.find ( "ref" ) ;
      cout << s1.substr ( pos ) ;
      system ( "PAUSE" ) ;

Author Comment

ID: 12150602
Thank you all,
Lets change my question a little bit.

string s1 = "this is a customer account,  'abc#123456789' ";
so i want to extract substring "abc#123456789" from single quotes (' ')
i like to use
s = s.substr(s.find_first_of("\'") + 1);
s = s.substr(s.find_last_of("\'") - 1);
My code is like the followings. but i have compiling errors, any experts can help ? or any function of extracting substring from single quotes (' ') i can use ?
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <algorithm>

using namespace std;

main(int arc, char *arv[])
      ifstream fin("fin.txt");
      ofstream fout("fout.txt");
      char row_read[512];
      char row_elem[50][50];
      int i =0;
while( fin.getline( row_read, sizeof( row_read ) ) )
      // get tokens, parse string with ","
      char *token = strtok( row_read, ',' );
      char *subtoken(token);
      while( token != NULL )
           subtoken = token.substr(token.find_first_of("\'") + 1);
           subtoken = token.substr( token.find_last_of("\'") - 1);
            //write the subtoken into row_elem[i]
             /* While there are tokens in "string" */
                   strcpy(row_elem[i], subtoken );
             /* Get next token: */
                   token = strtok( NULL, ',' );

                    fout<<setw(20)<< row_elem[8]<<endl;


return 0;

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