CODEWITHSUNDEEP
cparsing
KJF
KJF

Reputation: 2093

Parse a version number given as a string into 4 distinct integers using in c

I have a version number returned as a string which looks something like "6.4.12.9", four numbers, each separated by a "."

What I would like to do is to parse the string into 4 distinct integers. Giving me 

int1 = 6
int2 = 4
int3 = 12
int4 = 9

I'd normally use a regex for this but that option isn't available to me using C.

Upvotes: 1

Views: 1935

Answers (6)

unwind
unwind

Reputation: 399881

If you're on a POSIX system, and limiting yourself to POSIX is okay, you can use the POSIX standard regular expression library by doing:

#include <regex.h>

then read the relevant manual page for the API. I would not recommend a regexp-solution for this problem to begin with, but I wanted to point out for clarity that regular expressions are often available in C. Do note that this is not "standard C", so you can't use it everywhere, only on POSIX (i.e. "Unix-like") systems.

Upvotes: 1

R.. GitHub STOP HELPING ICE
R.. GitHub STOP HELPING ICE

Reputation: 215287

If none of them will exceed 255, inet_pton will parse it nicely for you. :-)

Upvotes: 0

Rumple Stiltskin
Rumple Stiltskin

Reputation: 10405

One solution using strtoul.

int main (int argc, char const* argv[])
{
    char ver[] = "6.4.12.9";
    char *next = ver;
    int v[4], i;
    for(i = 0; i < 4; i++, next++)
        v[i] = strtoul(next, &next, 10);
    return 0;
}

Upvotes: 1

nos
nos

Reputation: 229138

You can use sscanf

int a,b,c,d;
const char *version = "1.6.3.1";
if(sscanf(version,"%d.%d.%d.%d",&a,&b,&c,&d) != 4) {
  //error parsing
} else {
  //ok, use the integers a,b,c,d
}

Upvotes: 8

John Carter
John Carter

Reputation: 55291

You could used strtok() for this (followed by strtol()), just make sure you're aware of the semantics of strtok(), they're slightly unusual.

You could also use sscanf().

Upvotes: 0

ThiefMaster
ThiefMaster

Reputation: 318518

You can use strtoul() to parse the string and get a pointer to the first non-numeric character. Another solution would be tokenizing the string using strtok() and then using strtoul() or atoi() to get an integer.

Upvotes: 0

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