weston/shared/string-helpers.h
Bryce Harrington 82b9f2baec Add safe_strtoint() helper
Adds a safe strtol helper function, modeled loosely after Wayland
scanner's strtouint.  This encapsulates the various quirks of strtol
behavior, and streamlines the interface to just handling base-10 numbers
with a simple true/false error indicator and a uint32_t return by
reference.

Test cases are loosely derived from an earlier patch by Imran Zaman.

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
2016-08-06 18:19:19 -07:00

71 lines
2.1 KiB
C

/*
* Copyright © 2016 Samsung Electronics Co., Ltd
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef WESTON_STRING_HELPERS_H
#define WESTON_STRING_HELPERS_H
#include <stdbool.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>
/* Convert string to integer
*
* Parses a base-10 number from the given string. Checks that the
* string is not blank, contains only numerical characters, and is
* within the range of INT32_MIN to INT32_MAX. If the validation is
* successful the result is stored in *value; otherwise *value is
* unchanged and errno is set appropriately.
*
* \return true if the number parsed successfully, false on error
*/
static inline bool
safe_strtoint(const char *str, int32_t *value)
{
long ret;
char *end;
assert(str != NULL);
errno = 0;
ret = strtol(str, &end, 10);
if (errno != 0) {
return false;
} else if (end == str || *end != '\0') {
errno = EINVAL;
return false;
}
if ((long)((int32_t)ret) != ret) {
errno = ERANGE;
return false;
}
*value = (int32_t)ret;
return true;
}
#endif /* WESTON_STRING_HELPERS_H */