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/*
* Copyright (C) 2015 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 "file_magic.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <cstring>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include "unix_file/fd_file.h"
namespace art {
using android::base::StringPrintf;
File OpenAndReadMagic(const char* filename, uint32_t* magic, std::string* error_msg) {
CHECK(magic != nullptr);
File fd(filename, O_RDONLY, /* check_usage= */ false);
if (fd.Fd() == -1) {
*error_msg = StringPrintf("Unable to open '%s' : %s", filename, strerror(errno));
return File();
}
if (!ReadMagicAndReset(fd.Fd(), magic, error_msg)) {
StringPrintf("Error in reading magic from file %s: %s", filename, error_msg->c_str());
return File();
}
return fd;
}
bool ReadMagicAndReset(int fd, uint32_t* magic, std::string* error_msg) {
if (lseek(fd, 0, SEEK_SET) != 0) {
*error_msg = StringPrintf("Failed to seek to beginning of file : %s", strerror(errno));
return false;
}
int n = TEMP_FAILURE_RETRY(read(fd, magic, sizeof(*magic)));
if (n != sizeof(*magic)) {
*error_msg = StringPrintf("Failed to find magic");
return false;
}
if (lseek(fd, 0, SEEK_SET) != 0) {
*error_msg = StringPrintf("Failed to seek to beginning of file : %s", strerror(errno));
return false;
}
return true;
}
bool IsZipMagic(uint32_t magic) {
return (('P' == ((magic >> 0) & 0xff)) &&
('K' == ((magic >> 8) & 0xff)));
}
} // namespace art
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