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/* Zutils - Utilities dealing with compressed files
Copyright (C) 2009, 2010 Antonio Diaz Diaz.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _FILE_OFFSET_BITS 64
#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <stdint.h>
#include <unistd.h>
#include <sys/wait.h>
#include "zutils.h"
const char * invocation_name = 0;
const char * util_name = program_name;
int verbosity = 0;
// Returns the number of bytes really read.
// If (returned value < size) and (errno == 0), means EOF was reached.
//
int readblock( const int fd, uint8_t * const buf, const int size ) throw()
{
int rest = size;
errno = 0;
while( rest > 0 )
{
errno = 0;
const int n = read( fd, buf + size - rest, rest );
if( n > 0 ) rest -= n;
else if( n == 0 ) break;
else if( errno != EINTR && errno != EAGAIN ) break;
}
return ( rest > 0 ) ? size - rest : size;
}
// Returns the number of bytes really written.
// If (returned value < size), it is always an error.
//
int writeblock( const int fd, const uint8_t * const buf, const int size ) throw()
{
int rest = size;
errno = 0;
while( rest > 0 )
{
errno = 0;
const int n = write( fd, buf + size - rest, rest );
if( n > 0 ) rest -= n;
else if( errno && errno != EINTR && errno != EAGAIN ) break;
}
return ( rest > 0 ) ? size - rest : size;
}
bool feed_data( const int infd, const int outfd,
const uint8_t * magic_data, const int magic_size )
{
if( writeblock( outfd, magic_data, magic_size ) != magic_size )
{ show_error( "Write error", errno ); return false; }
enum { buffer_size = 4096 };
uint8_t buffer[buffer_size];
while( true )
{
const int size = readblock( infd, buffer, buffer_size );
if( size != buffer_size && errno )
{ show_error( "Read error", errno ); return false; }
if( size > 0 && writeblock( outfd, buffer, size ) != size )
{ show_error( "Write error", errno ); return false; }
if( size < buffer_size ) break;
}
return true;
}
bool set_data_feeder( int * const infdp, pid_t * const pidp )
{
std::string file_type;
const uint8_t * magic_data;
int magic_size;
const bool compressed =
test_format( *infdp, file_type, &magic_data, &magic_size );
if( compressed ) // compressed with `file_type'
{
int fda[2]; // pipe from feeder
int fda2[2]; // pipe from decompressor
if( pipe( fda ) < 0 || pipe( fda2 ) < 0 )
{ show_error( "Can't create pipe", errno ); return false; }
const int old_infd = *infdp;
*infdp = fda2[0];
const pid_t pid = fork();
if( pid == 0 ) // child (decompressor feeder)
{
const pid_t pid2 = fork();
if( pid2 == 0 ) // grandchild (decompressor)
{
if( dup2( fda[0], STDIN_FILENO ) >= 0 &&
dup2( fda2[1], STDOUT_FILENO ) >= 0 &&
close( fda[0] ) == 0 && close( fda[1] ) == 0 &&
close( fda2[0] ) == 0 && close( fda2[1] ) == 0 )
execlp( file_type.c_str(), file_type.c_str(), "-cdfq", (char *)0 );
show_exec_error( file_type.c_str() );
_exit( 2 );
}
if( pid2 < 0 )
{ show_fork_error( file_type.c_str() ); _exit( 2 ); }
if( close( fda[0] ) != 0 ||
close( fda2[0] ) != 0 || close( fda2[1] ) != 0 ||
!feed_data( old_infd, fda[1], magic_data, magic_size ) )
_exit( 2 );
if( close( fda[1] ) != 0 )
{ show_close_error( "decompressor feeder" ); _exit( 2 ); }
_exit( wait_for_child( pid2, file_type.c_str() ) );
}
// parent
close( fda[0] ); close( fda[1] ); close( fda2[1] );
if( pid < 0 )
{ show_fork_error( "decompressor feeder" ); return false; }
*pidp = pid;
}
else // not compressed
{
int fda[2]; // pipe from feeder
if( pipe( fda ) < 0 )
{ show_error( "Can't create pipe", errno ); return false; }
const int old_infd = *infdp;
*infdp = fda[0];
const pid_t pid = fork();
if( pid == 0 ) // child (feeder)
{
if( close( fda[0] ) != 0 ||
!feed_data( old_infd, fda[1], magic_data, magic_size ) )
_exit( 2 );
if( close( fda[1] ) != 0 )
{ show_close_error( "data feeder" ); _exit( 2 ); }
_exit( 0 );
}
// parent
close( fda[1] );
if( pid < 0 )
{ show_fork_error( "data feeder" ); return false; }
*pidp = pid;
}
return true;
}
void show_help_addr() throw()
{
std::printf( "\nReport bugs to zutils-bug@nongnu.org\n" );
std::printf( "Zutils home page: http://www.nongnu.org/zutils/zutils.html\n" );
}
void show_version( const char * const Util_name ) throw()
{
if( !Util_name || !*Util_name )
std::printf( "%s %s\n", Program_name, PROGVERSION );
else
std::printf( "%s (%s) %s\n", Util_name, program_name, PROGVERSION );
std::printf( "Copyright (C) %s Antonio Diaz Diaz.\n", program_year );
std::printf( "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n" );
std::printf( "This is free software: you are free to change and redistribute it.\n" );
std::printf( "There is NO WARRANTY, to the extent permitted by law.\n" );
}
void show_error( const char * const msg, const int errcode,
const bool help ) throw()
{
if( verbosity >= 0 )
{
if( msg && msg[0] )
{
std::fprintf( stderr, "%s: %s", util_name, msg );
if( errcode > 0 )
std::fprintf( stderr, ": %s", std::strerror( errcode ) );
std::fprintf( stderr, "\n" );
}
if( help && invocation_name && invocation_name[0] )
std::fprintf( stderr, "Try `%s --help' for more information.\n",
invocation_name );
}
}
void show_error2( const char * const msg, const char * const name ) throw()
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: %s `%s': %s.\n",
util_name, msg, name, std::strerror( errno ) );
}
void show_close_error( const char * const prog_name ) throw()
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: Can't close output of %s: %s.\n",
util_name, prog_name, std::strerror( errno ) );
}
void show_exec_error( const char * const prog_name ) throw()
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: Can't exec `%s': %s.\n",
util_name, prog_name, std::strerror( errno ) );
}
void show_fork_error( const char * const prog_name ) throw()
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: Can't fork `%s': %s.\n",
util_name, prog_name, std::strerror( errno ) );
}
void internal_error( const char * const msg )
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: internal error: %s.\n", util_name, msg );
std::exit( 3 );
}
unsigned char xdigit( const int value ) throw()
{
if( value >= 0 && value <= 9 ) return '0' + value;
if( value >= 10 && value <= 15 ) return 'A' + ( value - 10 );
return 0;
}
bool test_format( const int infd, std::string & file_type,
const uint8_t ** const magic_datap, int * const magic_sizep )
{
enum { buf_size = 5 };
static uint8_t buf[buf_size];
int i = 0;
file_type.clear();
if( readblock( infd, buf, 1 ) == 1 )
{
++i;
if( buf[0] == bzip2_magic[0] )
{
if( readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == bzip2_magic[1] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == bzip2_magic[2] )
{ file_type = "bzip2";
*magic_datap = bzip2_magic; *magic_sizep = bzip2_magic_size; }
}
else if( buf[0] == gzip_magic[0] )
{
if( readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == gzip_magic[1] )
{ file_type = "gzip";
*magic_datap = gzip_magic; *magic_sizep = gzip_magic_size; }
}
else if( buf[0] == lzip_magic[0] )
{
if( readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == lzip_magic[1] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == lzip_magic[2] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == lzip_magic[3] )
{ file_type = "lzip";
*magic_datap = lzip_magic; *magic_sizep = lzip_magic_size; }
}
else if( buf[0] == xz_magic[0] )
{
if( readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == xz_magic[1] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == xz_magic[2] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == xz_magic[3] &&
readblock( infd, &buf[i], 1 ) == 1 && buf[i++] == xz_magic[4] )
{ file_type = "xz";
*magic_datap = xz_magic; *magic_sizep = xz_magic_size; }
}
}
if( file_type.size() ) return true;
for( int j = 0; j < i; ++j )
{
file_type += xdigit( buf[j] >> 4 );
file_type += xdigit( buf[j] & 0x0F );
}
*magic_datap = buf; *magic_sizep = i;
return false;
}
int wait_for_child( const pid_t pid, const char * const name )
{
int status;
while( waitpid( pid, &status, 0 ) == -1 )
{
if( errno != EINTR )
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: Error waiting termination of `%s': %s.\n",
util_name, name, std::strerror( errno ) );
_exit( 1 );
}
}
if( WIFEXITED( status ) ) return WEXITSTATUS( status );
else return 1;
}
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