/* Zcmp - decompress and compare two files byte by byte
Copyright (C) 2010-2018 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 2 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 .
*/
#define _FILE_OFFSET_BITS 64
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#if defined(__MSVCRT__) || defined(__OS2__)
#include
#endif
#include "arg_parser.h"
#include "rc.h"
#include "zutils.h"
#ifndef LLONG_MAX
#define LLONG_MAX 0x7FFFFFFFFFFFFFFFLL
#endif
namespace {
#include "zcmpdiff.cc"
void show_help()
{
std::printf( "Zcmp compares two files ('-' means standard input), and if they differ,\n"
"tells the first byte and line number where they differ. Bytes and lines\n"
"are numbered starting with 1. If any given file is compressed, its\n"
"decompressed content is used. Compressed files are decompressed on the\n"
"fly; no temporary files are created.\n"
"\nThe supported formats are bzip2, gzip, lzip and xz.\n"
"\nUsage: zcmp [options] file1 [file2]\n"
"\nZcmp compares file1 to file2. If file2 is omitted zcmp tries the\n"
"following:\n"
"\n 1. If file1 is compressed, compares its decompressed contents with\n"
" the corresponding uncompressed file (the name of file1 with the\n"
" extension removed).\n"
"\n 2. If file1 is uncompressed, compares it with the decompressed\n"
" contents of file1.[lz|bz2|gz|xz] (the first one that is found).\n"
"\n 3. If no suitable file is found, compares file1 with data read from\n"
" standard input.\n"
"\nExit status is 0 if inputs are identical, 1 if different, 2 if trouble.\n"
"\nOptions:\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
" -b, --print-bytes print differing bytes\n"
" -i, --ignore-initial=[:] ignore differences in the first bytes\n"
" -l, --list list position, value of all differing bytes\n"
" -M, --format= process only the formats in \n"
" -n, --bytes= compare at most bytes\n"
" -N, --no-rcfile don't read runtime configuration file\n"
" -O, --force-format=[][,] force given formats (bz2, gz, lz, xz)\n"
" -q, --quiet suppress all messages\n"
" -s, --silent (same as --quiet)\n"
" -v, --verbose verbose mode (same as --list)\n"
" --bz2= set compressor and options for bzip2 format\n"
" --gz= set compressor and options for gzip format\n"
" --lz= set compressor and options for lzip format\n"
" --xz= set compressor and options for xz format\n"
"Numbers may be followed by a multiplier: k = kB = 10^3 = 1000,\n"
"Ki = KiB = 2^10 = 1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc...\n" );
show_help_addr();
}
long long getnum( const char * const ptr, const char ** const tailp = 0,
const long long llimit = 0,
const long long ulimit = LLONG_MAX )
{
char * tail;
errno = 0;
long long result = strtoll( ptr, &tail, 0 );
if( tail == ptr )
{
show_error( "Bad or missing numerical argument.", 0, true );
std::exit( 2 );
}
if( result < 0 ) errno = ERANGE;
if( !errno && tail[0] && std::isalpha( tail[0] ) )
{
const unsigned char ch = *tail++;
int factor;
bool bsuf; // 'B' suffix is present
if( tail[0] == 'i' ) { ++tail; factor = 1024; } else factor = 1000;
if( tail[0] == 'B' ) { ++tail; bsuf = true; } else bsuf = false;
int exponent = -1; // -1 = bad multiplier
switch( ch )
{
case 'Y': exponent = 8; break;
case 'Z': exponent = 7; break;
case 'E': exponent = 6; break;
case 'P': exponent = 5; break;
case 'T': exponent = 4; break;
case 'G': exponent = 3; break;
case 'M': exponent = 2; break;
case 'K': if( factor == 1024 ) exponent = 1; break;
case 'k': if( factor == 1000 ) exponent = 1; break;
case 'B': if( factor == 1000 && !bsuf ) exponent = 0; break;
}
if( exponent < 0 )
{
show_error( "Bad multiplier in numerical argument.", 0, true );
std::exit( 2 );
}
for( int i = 0; i < exponent; ++i )
{
if( ulimit / factor >= result ) result *= factor;
else { errno = ERANGE; break; }
}
}
if( !errno && ( result < llimit || result > ulimit ) ) errno = ERANGE;
if( errno )
{
show_error( "Numerical argument out of limits." );
std::exit( 2 );
}
if( tailp ) *tailp = tail;
return result;
}
void parse_ignore_initial( const char * const arg, long long ignore_initial[2] )
{
const char * tail;
ignore_initial[0] = getnum( arg, &tail );
if( *tail == ':' || *tail == ',' )
ignore_initial[1] = getnum( ++tail );
else if( *tail == 0 ) ignore_initial[1] = ignore_initial[0];
else
{
show_error( "Bad separator in argument of '--ignore-initial'", 0, true );
std::exit( 2 );
}
}
bool skip_ignore_initial( const long long ignore_initial, const int infd )
{
if( ignore_initial > 0 )
{
enum { buffer_size = 4096 };
long long rest = ignore_initial;
uint8_t buffer[buffer_size];
while( rest > 0 )
{
const int size = std::min( rest, (long long)buffer_size );
const int rd = readblock( infd, buffer, size );
if( rd != size && errno ) return false;
if( rd < size ) break;
rest -= rd;
}
}
return true;
}
// Put into buf the unsigned char c, making unprintable bytes
// visible by quoting like cat -t does.
void sprintc( char * const buf, unsigned char c )
{
int i = 0;
if( c < 32 || c >= 127 )
{
if( c >= 128 ) { c -= 128; buf[i++] = 'M'; buf[i++] = '-'; }
if( c < 32 ) { c += 64; buf[i++] = '^'; }
else if( c == 127 ) { c = '?'; buf[i++] = '^'; }
}
buf[i++] = c;
buf[i++] = 0;
}
int block_compare( const uint8_t * const buffer0,
const uint8_t * const buffer1,
unsigned long long * const line_numberp )
{
const uint8_t * p0 = buffer0;
const uint8_t * p1 = buffer1;
if( verbosity == 0 )
{
int nl_count = 0;
while( *p0 == *p1 )
{ if( *p0 == '\n' ) { ++nl_count; } ++p0; ++p1; }
*line_numberp += nl_count;
}
else while( *p0 == *p1 ) { ++p0; ++p1; }
return p0 - buffer0;
}
int cmp( const long long max_size, const int infd[2],
const std::string filenames[2], const bool print_bytes )
{
const int buffer_size = 4096;
unsigned long long byte_number = 1;
unsigned long long line_number = 1;
// remaining number of bytes to compare
long long rest = ( max_size >= 0 ) ? max_size : buffer_size;
// buffers with space for sentinels at the end
uint8_t * const buffer0 = new uint8_t[2*(buffer_size+1)];
uint8_t * const buffer1 = buffer0 + buffer_size + 1;
uint8_t * buffer[2];
buffer[0] = buffer0; buffer[1] = buffer1;
int different = 0;
while( rest > 0 )
{
const int size = std::min( (long long)buffer_size, rest );
if( max_size >= 0 ) rest -= size;
int rd[2]; // number of bytes read from each file
for( int i = 0; i < 2; ++i )
{
rd[i] = readblock( infd[i], buffer[i], size );
if( rd[i] != size && errno )
{
show_error2( "Error reading file", filenames[i].c_str() );
return 2;
}
}
const int min_rd = std::min( rd[0], rd[1] );
buffer0[min_rd] = 0; // sentinels for the block compare
buffer1[min_rd] = 1;
int first_diff = block_compare( buffer0, buffer1, &line_number );
byte_number += first_diff;
if( first_diff < min_rd )
{
if( verbosity < 0 ) return 1; // return status only
if( verbosity == 0 ) // show first difference
{
if( !print_bytes )
std::printf( "%s %s differ: byte %llu, line %llu\n",
filenames[0].c_str(), filenames[1].c_str(),
byte_number, line_number );
else
{
const unsigned char c0 = buffer0[first_diff];
const unsigned char c1 = buffer1[first_diff];
char buf0[5], buf1[5];
sprintc( buf0, c0 ); sprintc( buf1, c1 );
std::printf( "%s %s differ: byte %llu, line %llu is %3o %s %3o %s\n",
filenames[0].c_str(), filenames[1].c_str(),
byte_number, line_number, c0, buf0, c1, buf1 );
}
return 1;
}
else // verbosity > 0 ; show all differences
{
different = 1;
for( ; first_diff < min_rd; ++byte_number, ++first_diff )
{
const unsigned char c0 = buffer0[first_diff];
const unsigned char c1 = buffer1[first_diff];
if( c0 != c1 )
{
if( !print_bytes )
std::printf( "%llu %3o %3o\n", byte_number, c0, c1 );
else
{
char buf0[5], buf1[5];
sprintc( buf0, c0 ); sprintc( buf1, c1 );
std::printf( "%llu %3o %-4s %3o %s\n",
byte_number, c0, buf0, c1, buf1 );
}
}
}
}
}
if( rd[0] != rd[1] )
{
if( verbosity >= 0 )
std::fprintf( stderr, "%s: EOF on %s\n",
program_name, filenames[rd[1]= parser.arguments() )
{ show_error( "No files given.", 0, true ); return 2; }
if( argind + 2 < parser.arguments() )
{ show_error( "Too many files.", 0, true ); return 2; }
const int files = parser.arguments() - argind;
std::string filenames[2]; // file names of the two input files
filenames[0] = parser.argument( argind );
if( files == 2 ) filenames[1] = parser.argument( argind + 1 );
int infd[2]; // file descriptors of the two files
infd[0] = ( filenames[0] == "-" ) ?
STDIN_FILENO : open_instream( filenames[0] );
if( infd[0] < 0 ) return 2;
if( ( files == 1 && filenames[0] == "-" ) ||
( files == 2 && check_identical( filenames[0].c_str(),
filenames[1].c_str() ) ) )
{
if( ignore_initial[0] == ignore_initial[1] ) return 0;
else { show_error( "Can't compare parts of same file." ); return 2; }
}
if( files == 2 )
{
infd[1] = ( filenames[1] == "-" ) ?
STDIN_FILENO : open_instream( filenames[1] );
if( infd[1] < 0 ) return 2;
}
else
{
if( format_types[0] >= 0 || format_types[1] >= 0 )
{ show_error( "Two files must be given when format is specified.", 0, true );
return 2; }
filenames[1] = filenames[0];
infd[1] = open_other_instream( filenames[1] );
if( infd[1] < 0 ) { infd[1] = STDIN_FILENO; filenames[1] = "-"; }
}
int old_infd[2]; // copy of file descriptors of the two files
old_infd[0] = infd[0]; old_infd[1] = infd[1];
Children children[2];
if( !set_data_feeder( filenames[0], &infd[0], children[0], format_types[0] ) ||
!set_data_feeder( filenames[1], &infd[1], children[1], format_types[1] ) )
return 2;
for( int i = 0; i < 2; ++i )
if( !skip_ignore_initial( ignore_initial[i], infd[i] ) )
{
show_error2( "Can't skip initial bytes from file", filenames[i].c_str() );
return 2;
}
int retval = cmp( max_size, infd, filenames, print_bytes );
for( int i = 0; i < 2; ++i )
if( !good_status( children[i], retval == 0 && max_size < 0 ) ) retval = 2;
for( int i = 0; i < 2; ++i )
{
if( close( infd[i] ) != 0 )
{ show_close_error(); retval = 2; }
if( filenames[i] != "-" && close( old_infd[i] ) != 0 )
{
show_error2( "Can't close input file", filenames[i].c_str() );
retval = 2;
}
}
if( std::fclose( stdout ) != 0 )
{
show_error( "Can't close stdout", errno );
retval = 2;
}
return retval;
}