strtol in C: solved exercise for converting text to integer

strtol in C: solved exercise for converting text to integer

If you are looking for strtol in c: solved exercise for converting text to integer, here is a practical, compilable example focused on the reusable idea behind the exercise.

Problem statement

Convert 123abc to an integer and print the parsed number and remaining text.

C solution

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#include <stdio.h>
#include <stdlib.h>

int main(void) {
    const char *texto = "123abc";
    char *fin;
    long valor = strtol(texto, &fin, 10);
    printf("%ld\n", valor);
    printf("%s\n", fin);
    return 0;
}

Expected output

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123
abc

Common mistakes

  • Not testing edge cases such as small or empty inputs.
  • Not validating indices, pointers, or limits carefully enough.
  • Copying the mechanics without understanding the general pattern.

Practical use

This pattern appears frequently in text handling, input validation, and buffer manipulation.

Guided practice and full book

If you want a complete path with progressive difficulty:

FAQ

Is this exercise useful in practice?

Yes. It is designed to teach a reusable C pattern rather than a one-off toy example.

How should I practice it better?

Change the input data, add edge cases, and rewrite it from scratch without looking at the solution.

How should I practice this exercise type to improve faster?

Start with small inputs, run edge cases (empty, one item, max capacity), then rewrite the solution from scratch without copying.