Thread: Progress bar test segfaults

Ok, so this is supposed to display a wget-style progress bar. It segfaults and I don't know where. Any help finding it is appreciated. Thanks!

Code:

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

inline int getpercent(int a, int b) {
  return (int)((a / b) * 100);
}

/*Dest should be the length of the progress bar*/
/*Returns 0 on error, 1 on success*/
int pbar(const int percent, char *dest) {
  int cur, size, tostop, destlen = strlen(dest);
  size = destlen - 3;
  dest[0] = '|';
  dest[destlen - 2] = '|';
  dest[destlen - 1] = '\0';
  tostop = ((int)((percent / size) * 100));
  
  for (cur = 1; cur <= size; cur++) {
    if (cur <= tostop) dest[cur] = '=';
    else dest[cur] = ' ';
  }
  return 1;
}

void progbar(const int amount) {
  int current, cols = atoi(getenv("COLUMNS"));
  char *bstr = malloc(cols + 1);
  for (current = 0; current < cols; current++) bstr[current] = ' ';
  bstr[cols] = '\0';
  for (current = 0; current < amount; current++) {
    printf("\r%s", pbar(getpercent(current, amount), bstr));
    usleep(500000);
  }
  free(bstr);
  return;
}  

int main(int argc, char **argv) {
  int total;
  scanf("%d", &total);
  progbar(total);
  return 0;
}

yeah, apparently that's it.

Code:

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

int main() {
	printf("%d\n", atoi(getenv("COLUMNS")));
	return 0;
}

that segfaults.

any idea how to do a wget-style progress bar then?

oops yeah lol pbar originally returned a char*
still.... how do i manage to do it without setting them in advance?

yeah that's what i tried to do the other day (using termcap)
i'm just using this in case my program is run with -v... thought progress bars would be cool :-D

anybody know a really good termcap tutorial? all I need is to get term width.