I'm trying to scanf multiple ints from a string, but I don't know how many it will have, because it varies from case to case. I want to scanf multiple numbers and put them in an array.
I've been trying to do it this way but it's not working... Assuming I want to scan C numbers from the string "line".
for(a=0;a<c;a++)
sscanf(line, " %d ",&v[a]);
I wrote a piece of code to help you understand it more clearly.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void){
int v[10];
char buffer[4096];
char * line = NULL;
int i, j;
if(fgets(buffer, 4096, stdin) == NULL){
return -1;
}
for(i = 0, line = strtok(buffer, " "); i < 10; i++){
if(line == NULL){
break;
}
sscanf(line, "%d", &v[i]);
line = strtok(NULL, " ");
}
j = i;
for(i = 0; i < j; i++){
printf("%d\n", v[i]);
}
return 0;
}
[neo]:./a.out
1 2 3 4 5 9999
1
2
3
4
5
9999
Suppose you have enough space to store as much as integer.
char * c_num = NULL;
for(c_num = strtok(line, " \t\n"), a = 0; c_num != NULL && a < c; c_num = strtok(NULL, " \t\n"), a++){
v[a] = atoi(c_num);
}
for loop if I've ever seen one! :-Dstrtok, when I first saw it, I had same confusion about the for loop
strtok, while cutting string, you have to invoke strtok(@your cutting string, @separator) first, then loop invoke strtok(NULL, @separator) to get remaining cut strings.So you have miss the first step.Here is manual man7.org/linux/man-pages/man3/strtok.3.htmlI finally nailed it! Thanks for all your help guys ;)
f = fopen(argv[1],"r");
fgets(line,c,f);
line2 = strtok(line, " ");
while (line2 != NULL){
sscanf(line2, "%d",&v[i]);
line2=strtok(NULL, " ");
i++;
}
<space>Number<space>from the beginning of the line. So for example if you line is ` 1 2 3 4, you will always read1`.