number in string

[GanglyLamb]

so i read files with fopen
i read a string with a certain lenght( wich is defined with strlen)
then i say if theres a character wich is digit (isdigit(c))
then he has to read the string until it finished presuming there are only digits after the first digit
now my problem is i want to store the numbers in a variable how should i do
heres some of the code...

#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define size 100

int main(){
	FILE *data;
	char lijn[size];
	char c;
	int lengte;
	int teller=0;
	int OFM;


	data=fopen("dat.txt","r");
	if(data==0){
					printf("Kon het bestand dat.txt niet openen");
					exit(-1);
					}

	do{
		fgets(lijn,size,data);
		lengte=strlen(lijn);
		for(int i=0;i<lengte;i++){
											c=lijn[i];
											printf("%c",c);
											if(i==lengte){printf("\n");}
											if(isdigit(c){
																/*here has to be some code that reas until the string is finished and puts the number in a variable*/
											}
		}
		while(!feof(data));


	fclose(data);
	return 0;
	}

thx

[Sayeh]

now my problem is i want to store the numbers in a variable how should i do

a = 5;

---

For real help, you need to be more specific.

[GanglyLamb]

say my file looks like this because a=5 that was something i knew
my file looks like this "dat.txt"

the first line blablabla:12356
second line some strange words in here:1254

now i take a string wich is one line in the file then i check every character in the string for digits and if a character is a digit then it has to read on and store for instance 12356
so if the character in the first string becomes a nulber like here 1 then it has to read on and store the numbers left in a int....
i hope its much clearer now my prob ...

[Monster]

while(fgets(lijn,size,data) != NULL) /* fgets returns NULL on EOF */
{
   /* do your stuff */
}

You want to store all digits in one integer?

#include <stdio.h>
...
int i;
if(sscanf(lijn, "%d", &i) == 1) /* sscanf returns number of items successfully scanned */
   printf("%d\n", i);

Or:

#include <stdlib.h>
...
int i
i = atoi(lijn); /* use the isdigit function to check if lijn starts with a digit */

Succes,
Monster

[GanglyLamb]

thx monster i guess uve got the right answer ill check if it works when im done with working for school......
ive got an exam of french tommorow

[Monster]

A small example:

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

int main(void)
{
   char buf[BUFSIZ]; /* BUFSIZ is defined in stdio.h (1024) */
   char *ptr = NULL;
   int getal = 0;

   FILE *fp = NULL;

   if((fp = fopen("dat.txt", "r")) != NULL)
   {
      while(fgets(buf, BUFSIZ, fp) != NULL)
      {
         /* walk trough buf and stop when digit found */
         for(ptr = buf; !isdigit(*ptr); ptr++) ;

         if(isdigit(*ptr)) /* found a digit? */
         {
            sscanf(ptr, "%d", &getal); /* or getal = atoi(ptr); */
            printf("line  = %s", buf);
            printf("getal = %d\n", getal);
         }
      }
      fclose(fp);
   }
   return 0;
}

Goodluck with your exam

[Hammer]

>>sscanf(ptr, "%d", &getal);
If you want to use this function, make sure you check its return code to ensure it did what you asked.

[GanglyLamb]

ive tried to do this all but it gave me some errors so i quit thinking about it because i dont have the time right now but ill review my thread as soon as i have some spare-time that i can use to program+ i think i did use sscanf somewhere because of the example give above but i think it gave me some strange things.....
(now i know again it was only the first digit 8 of the number 80 that was given ....somewhere) but as said ill take a look at it when i have some time ...

[Monster]

Originally posted by Hammer
>>sscanf(ptr, "%d", &getal);
If you want to use this function, make sure you check its return code to ensure it did what you asked.

You're right, in my first post I did check the scanf. Forgot that in the second post.