stream - Reading txt file in C++ to strings and floats -

i need read *.txt file. contains words , numbers, , looks this:

firstword:12,13.0secondword18.7thirdword2,3,89

i need extract words strings, , numbers floats. main problem cannot solve there no delimiters before "words" (otherwise i'd use getline).

thank you!

note: words not contain numbers, example, word 'num1' impossible.

with sstream, more requires delimiter, there none in file.

by using functions found in standard c library, can character character without delimiter. , not elegant.

this 1 way of extracting words , doubles text file text.txt contaning firstword:12,13.0secondword18.7thirdword2,3,89.

this solution uses funtion isalpha() extract alphabet related , stores in array extractedwords[].

for doubles, uses isdigit() , atof() extract number related , stores in array extracteddoubles[].

#include<string> #include<fstream> #include<iostream>  #include <stdlib.h> using namespace std;  char mainbuffer[1024]={' '}; size_t fsize ; string extractedwords[100]; double extracteddoubles[100]={0};   string buf2str(const char* buffer); void loadfiletobuffer(char *filename); void extractwords(); void extractfloats();    int main(){      loadfiletobuffer("text.txt" );     extractwords();       extractfloats();     cout<<"\n";     return 0; }                                                                                 string buf2str(const char* buffer){     return string(buffer); }   void loadfiletobuffer(char *filename){     ifstream infile;     infile.open(filename);      infile.read(mainbuffer, sizeof mainbuffer);     if (infile.eof()){          fsize = infile.gcount();          cout<<"fsize = "<<fsize<<" , data =  " << mainbuffer <<" \n ";     }     else if (infile.fail()){         // other error...     }     else{         // buf must full, file larger...     }      infile.close(); }  void extractwords(){     char character;     int i=0;     int j=0;     char shortbuffer[16]={' '};     int seek=0;        cout<<"\n";     seek=0;     i=0;     j=0;     while ( seek<=fsize ) {         character=mainbuffer[seek];         if ( isalpha(character) ) {              shortbuffer[i]=character;             i++;         }          else{             shortbuffer[i]='\0';             if (strlen(shortbuffer)>2){                 extractedwords[j]=buf2str(shortbuffer);                 i=0;                 j++;             }          }           seek++;     }     for(int ii=0;ii<j;ii++) cout<<extractedwords[ii] <<"\n";     cout<<"\n"; }   void extractfloats(){     char character;     int i=0;     int j=0;     char shortbuffer[16]={' '};     double dvalue=0;     int seek=0;      cout<<"\n";     seek=0;     i=0;     j=0;      while ( seek<=fsize ) {         character=mainbuffer[seek];         if ( isdigit(character) || character=='.' ){               shortbuffer[i]=character;               i++;         }         else{              shortbuffer[i]='\0';              dvalue=atof(shortbuffer);              if (dvalue != 0) {                  extracteddoubles[j]=dvalue;              j++;              i=0;              }                    }         seek++;     }     for(int ii=0;ii<j;ii++) cout <<extracteddoubles[ii]<<"\n";     cout<<"\n"; }