bool
mozilla::ReadSysFile(
const char* aFilename,
char* aBuf,
size_t aBufSize)
{
int fd = MOZ_TEMP_FAILURE_RETRY(open(aFilename, O_RDONLY));
if (fd < 0) {
return false;
}
ScopedClose autoClose(fd);
if (aBufSize == 0) {
return true;
}
ssize_t bytesRead;
size_t offset = 0;
do {
bytesRead = MOZ_TEMP_FAILURE_RETRY(
read(fd, aBuf + offset, aBufSize - offset));
if (bytesRead == -1) {
return false;
}
offset += bytesRead;
} while (bytesRead > 0 && offset < aBufSize);
MOZ_ASSERT(offset <= aBufSize);
if (offset > 0 && aBuf[offset - 1] == '\n') {
offset--;
}
if (offset == aBufSize) {
MOZ_ASSERT(offset > 0);
offset--;
}
aBuf[offset] = '\0';
return true;
}
/**
* Create a file with the specified contents.
*/
static bool
WriteFile(
const char* aFilename,
const void* aContents,
size_t aContentsLen)
{
int fd;
ssize_t ret;
size_t offt;
fd = MOZ_TEMP_FAILURE_RETRY(
open(aFilename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR));
if (fd == -1) {
fprintf(stderr, "open(): %s: %s\n", aFilename, strerror(errno));
return false;
}
offt = 0;
do {
ret = MOZ_TEMP_FAILURE_RETRY(
write(fd, (char*)aContents + offt, aContentsLen - offt));
if (ret == -1) {
fprintf(stderr, "write(): %s: %s\n", aFilename, strerror(errno));
close(fd);
return false;
}
offt += ret;
} while (offt < aContentsLen);
ret = MOZ_TEMP_FAILURE_RETRY(close(fd));
if (ret == -1) {
fprintf(stderr, "close(): %s: %s\n", aFilename, strerror(errno));
return false;
}
return true;
}
