platform_system_core/libcutils/cpu_info.c

83 lines
2.5 KiB
C

/*
** Copyright 2007, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <cutils/cpu_info.h>
// we cache the serial number here.
// this is also used as a fgets() line buffer when we are reading /proc/cpuinfo
static char serial_number[100] = { 0 };
extern const char* get_cpu_serial_number(void)
{
if (serial_number[0] == 0)
{
FILE* file;
char* chp, *end;
char* whitespace;
// read serial number from /proc/cpuinfo
file = fopen("proc/cpuinfo", "r");
if (! file)
return NULL;
while ((chp = fgets(serial_number, sizeof(serial_number), file)) != NULL)
{
// look for something like "Serial : 999206122a03591c"
if (strncmp(chp, "Serial", 6) != 0)
continue;
chp = strchr(chp, ':');
if (!chp)
continue;
// skip colon and whitespace
while ( *(++chp) == ' ') {}
// truncate trailing whitespace
end = chp;
while (*end && *end != ' ' && *end != '\t' && *end != '\n' && *end != '\r')
++end;
*end = 0;
whitespace = strchr(chp, ' ');
if (whitespace)
*whitespace = 0;
whitespace = strchr(chp, '\t');
if (whitespace)
*whitespace = 0;
whitespace = strchr(chp, '\r');
if (whitespace)
*whitespace = 0;
whitespace = strchr(chp, '\n');
if (whitespace)
*whitespace = 0;
// shift serial number to beginning of the buffer
memmove(serial_number, chp, strlen(chp) + 1);
break;
}
fclose(file);
}
return (serial_number[0] ? serial_number : NULL);
}