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/*
* strtosize() - convert string to size (uintmax_t).
*
* Supported suffixes:
*
* XiB or X for 2^N
* where X = {K,M,G,T,P,E,Y,Z}
* or X = {k,m,g,t,p,e} (undocumented for backward compatibility only)
* for example:
* 10KiB = 10240
* 10K = 10240
*
* XB for 10^N
* where X = {K,M,G,T,P,E,Y,Z}
* for example:
* 10KB = 10000
*
* Note that the function does not accept numbers with '-' (negative sign)
* prefix.
*
* Returns 0 on success, -1 in case of error, -2 in case of overflow.
*
* Copyright (C) 2010 Karel Zak <kzak@redhat.com>
*/
#include <stdio.h>
#include <inttypes.h>
#include <ctype.h>
#include <errno.h>
static int do_scale_by_power (uintmax_t *x, int base, int power)
{
while (power--) {
if (UINTMAX_MAX / base < *x)
return -2;
*x *= base;
}
return 0;
}
int strtosize(const char *str, uintmax_t *res)
{
char *p;
uintmax_t x;
int base = 1024, rc = 0;
*res = 0;
if (!str || !*str)
goto err;
/* Only positive numbers are acceptable
*
* Note that this check is not perfect, it would be better to
* use lconv->negative_sign. But coreutils use the same solution,
* so it's probably good enough...
*/
p = (char *) str;
while (isspace((unsigned char) *p))
p++;
if (*p == '-')
goto err;
p = NULL;
errno = 0;
x = strtoumax(str, &p, 0);
if (p == str ||
(errno != 0 && (x == UINTMAX_MAX || x == 0)))
goto err;
if (!p || !*p)
goto done; /* without suffix */
/*
* Check size suffixes
*/
if (*(p + 1) == 'i' && *(p + 2) == 'B' && !*(p + 3))
base = 1024; /* XiB, 2^N */
else if (*(p + 1) == 'B' && !*(p + 2))
base = 1000; /* XB, 10^N */
else if (*(p + 1))
goto err; /* unexpected suffix */
switch(*p) {
case 'K':
case 'k':
rc = do_scale_by_power(&x, base, 1);
break;
case 'M':
case 'm':
rc = do_scale_by_power(&x, base, 2);
break;
case 'G':
case 'g':
rc = do_scale_by_power(&x, base, 3);
break;
case 'T':
case 't':
rc = do_scale_by_power(&x, base, 4);
break;
case 'P':
case 'p':
rc = do_scale_by_power(&x, base, 5);
break;
case 'E':
case 'e':
rc = do_scale_by_power(&x, base, 6);
break;
case 'Z':
rc = do_scale_by_power(&x, base, 7);
break;
case 'Y':
rc = do_scale_by_power(&x, base, 8);
break;
default:
goto err;
}
done:
*res = x;
return rc;
err:
return -1;
}
#ifdef TEST_PROGRAM
#include <stdio.h>
#include <stdlib.h>
#include <err.h>
int main(int argc, char *argv[])
{
uintmax_t size = 0;
if (argc < 2) {
fprintf(stderr, "usage: %s <number>[suffix]\n", argv[0]);
exit(EXIT_FAILURE);
}
if (strtosize(argv[1], &size))
errx(EXIT_FAILURE, "invalid size '%s' value", argv[1]);
printf("%25s : %20ju\n", argv[1], size);
return EXIT_FAILURE;
}
#endif /* TEST_PROGRAM */
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