c++ - Parsing string to get comma-separated integer character pairs -

i'm working on project i'm given file begins header in format: a1,b3,t11, 2,,5,\3,*4,344,00,. going sequence of single ascii character followed integer separated comma sequence ending 00,.

basically have go through , put each character/integer pair data type have takes both of these parameters , make vector of these. example, header gave above vector ('a',1), ('b',3),('t',11),(',',5)(' ',2),('\',3),('*',4),('3',44) elements.

i'm having trouble parsing it. far i've:

extracted header text file first character until before ',00,' header ends. can header string in string format or vector of characters (whichever easier parse)

tried using sscanf parse next character , next int adding vector before using substrings remove part of string i've analyzed (this messy , did not me right result)

tried going through string vector , checking each element see if integer, character, or comma , acting accordingly doesn't work multiple-digit integers or when character int

i know can split string based on commas i'm not sure how , still split integers characters while retaining both , accounting integers need treat characters.

any advice or useful standard library or string functions appreciated.

one possibility, of many, store data in structure. uses array of structures structure allocated needed malloc , realloc.
parsing string can accomplished using pointers , strtol parse integer , give pointer character following integer. pointer can advanced use in next iteration ascii character , integer.

#include <stdio.h> #include <string.h> #include <stdlib.h>  #define size 100  struct pair {     char ascii;     int  integer; };  int main( void) {     char input[] = "a1,b3,!0,t11, 2,,5,\\3,*4,34400,";     char *pt = input;//start pt pointing first character of input     char *end = input;     int each = 0;     int loop = 0;     int length = 0;     struct pair pairs[size] = { { '\0', 0}};      //assuming input end in 00, ( or ,00,)     //remove 3 ( or 4 ??) characters     length = strlen ( input);     if ( length > 3) {         input[length - 3] = '\0';     }     ( each = 0; each < size; each++) {         //get ascii character , advance 1 character         pairs[each].ascii = *pt;         pt++;         //get integer         pairs[each].integer = strtol ( pt, &end, 10);         //end==pt indicates expected integer missing         if ( end == pt) {             printf ( "expected integer\n");             break;         }         //at end of string?         if ( *end == '\0') {             //if there elements remaining, add 1 each 1 more used             if ( each < size - 1) {                 each++;             }             break;         }         //the character following integer should comma         if ( *end != ',') {             //if there elements remaining, add 1 each 1 more used             if ( each < size - 1) {                 each++;             }             printf ( "format problem\n");             break;         }         //for next iteration, advance pt 1 character past end         pt = end + 1;     }     //loop through , print used structures     ( loop = 0; loop < each; loop++) {         printf ( "ascii[%d] = %c   ", loop, pairs[loop].ascii);         printf ( "integer[%d] = %d\n", loop, pairs[loop].integer);     }      return 0; } 

another option use dynamic allocation.
uses sscanf parse input. %n capture number of characters processed scan. offset , add variables can used iterate through input. last scan capture ascii character , integer , return sscanf 2.

#include <stdio.h> #include <string.h> #include <stdlib.h>  struct pair {     char ascii;     int  integer; };  int main( void) {     char input[] = "a1,b3,!0,t11, 2,,5,\\3,*4,34400,";     char comma = '\0';     char ascii = '\0';     int integer = 0;     int result = 0;     int loop = 0;     int length = 0;     int used = 0;     int add = 0;     int offset = 0;     struct pair *pairs = null;//so realloc work on first call     struct pair *temp = null;      //assuming input end in 00, ( or ,00,)     //remove 3 ( or 4 ??) characters     length = strlen ( input);     if ( length > 3) {         input[length - 3] = '\0';     }     while ( ( result = sscanf ( &input[offset], "%c%d%c%n"     , &ascii, &integer, &comma, &add)) >= 2) {//the last scan 2 items         if ( ( temp = realloc ( pairs, ( used + 1) * sizeof ( *pairs))) == null) {             fprintf ( stderr, "problem allocating\n");             break;         }         pairs = temp;          pairs[used].ascii = ascii;         pairs[used].integer = integer;         //one more element used         used++;         //the character following integer should comma         if ( result == 3 && comma != ',') {             printf ( "format problem\n");             break;         }         //for next iteration, add offset         offset += add;     }     ( loop = 0; loop < used; loop++) {         printf ( "ascii[%d] = %c   ", loop, pairs[loop].ascii);         printf ( "value[%d] = %d\n", loop, pairs[loop].integer);     }      free ( pairs);      return 0; }