private void writeHeader(final CpioArchiveEntry e) throws IOException {
switch (e.getFormat()) {
case FORMAT_NEW:
out.write(ArchiveUtils.toAsciiBytes(MAGIC_NEW));
count(6);
writeNewEntry(e);
break;
case FORMAT_NEW_CRC:
out.write(ArchiveUtils.toAsciiBytes(MAGIC_NEW_CRC));
count(6);
writeNewEntry(e);
break;
case FORMAT_OLD_ASCII:
out.write(ArchiveUtils.toAsciiBytes(MAGIC_OLD_ASCII));
count(6);
writeOldAsciiEntry(e);
break;
case FORMAT_OLD_BINARY:
final boolean swapHalfWord = true;
writeBinaryLong(MAGIC_OLD_BINARY, 2, swapHalfWord);
writeOldBinaryEntry(e, swapHalfWord);
break;
default:
throw new IOException("unknown format " + e.getFormat());
}
}
private void writeAsciiLong(final long number, final int length, final int radix)
throws IOException {
final StringBuilder tmp = new StringBuilder();
String tmpStr;
if (radix == 16) {
tmp.append(Long.toHexString(number));
} else if (radix == 8) {
tmp.append(Long.toOctalString(number));
} else {
tmp.append(Long.toString(number));
}
if (tmp.length() <= length) {
final int insertLength = length - tmp.length();
for (int pos = 0; pos < insertLength; pos++) {
tmp.insert(0, "0");
}
tmpStr = tmp.toString();
} else {
tmpStr = tmp.substring(tmp.length() - length);
}
final byte[] b = ArchiveUtils.toAsciiBytes(tmpStr);
out.write(b);
count(b.length);
}
/**
* Checks if the signature matches what is expected for a tar file.
*
* @param signature the bytes to check
* @param length the number of bytes to check
* @return true, if this stream is a tar archive stream, false otherwise
*/
public static boolean matches(byte[] signature, int length) {
if (length < TarConstants.VERSION_OFFSET + TarConstants.VERSIONLEN) {
return false;
}
if (ArchiveUtils.matchAsciiBuffer(
TarConstants.MAGIC_POSIX, signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&& ArchiveUtils.matchAsciiBuffer(
TarConstants.VERSION_POSIX,
signature,
TarConstants.VERSION_OFFSET,
TarConstants.VERSIONLEN)) {
return true;
}
if (ArchiveUtils.matchAsciiBuffer(
TarConstants.MAGIC_GNU, signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&& (ArchiveUtils.matchAsciiBuffer(
TarConstants.VERSION_GNU_SPACE,
signature,
TarConstants.VERSION_OFFSET,
TarConstants.VERSIONLEN)
|| ArchiveUtils.matchAsciiBuffer(
TarConstants.VERSION_GNU_ZERO,
signature,
TarConstants.VERSION_OFFSET,
TarConstants.VERSIONLEN))) {
return true;
}
// COMPRESS-107 - recognise Ant tar files
if (ArchiveUtils.matchAsciiBuffer(
TarConstants.MAGIC_ANT, signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&& ArchiveUtils.matchAsciiBuffer(
TarConstants.VERSION_ANT,
signature,
TarConstants.VERSION_OFFSET,
TarConstants.VERSIONLEN)) {
return true;
}
return false;
}