c,string,char , Get part of a string with dynamic length in C


Get part of a string with dynamic length in C

Question:

Tag: c,string,char

I got the following string from the user: char *abc = "a234bc567d"; but all the numbers can have different lengths than in this example (letters are constants). How can I get each part of numbers? (again, it can be 234 or 23743 or something else..)

I tried to use strchr and strncpy but I need to allocate memory for this (for strncpy), and I hope there is a better solution.

Thanks.


Answer:

You can do something like this:

char *abc = "a234bc567d";
char *ptr = abc; // point to start of abc

// While not at the end of the string
while (*ptr != '\0') 
{
  //  If position is the start of a number
  if (isdigit(*ptr))
  {
    // Get value (assuming base 10), store end position of number in ptr
    int value = strtol(ptr, &ptr, 10); 

    printf("Found value %d\n", value);
  }
  else
  {
    ptr++; // Increase pointer
  }
}

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