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/* Zcat - decompress and concatenate files to standard output
Copyright (C) 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/>.
*/
struct Cat_options
{
int number_lines; // 0 = no, 1 = nonblank, 2 = all
bool show_ends;
bool show_nonprinting;
bool show_tabs;
bool squeeze_blank;
Cat_options() throw()
: number_lines( 0 ), show_ends( false ), show_nonprinting( false ),
show_tabs( false ), squeeze_blank( false ) {}
};
class Line_number // unlimited size line counter
{
std::string str;
int first_digit_pos;
public:
Line_number() : str( " 0\t" ), first_digit_pos( 5 ) {}
void next()
{
for( int i = str.size() - 2; i >= first_digit_pos; --i )
{
if( str[i] < '9' ) { ++str[i]; return; }
str[i] = '0';
}
if( first_digit_pos > 0 ) str[--first_digit_pos] = '1';
else str.insert( 0U, 1, '1' );
}
int sprint( uint8_t * const buf )
{
std::memcpy( buf, str.c_str(), str.size() );
return str.size();
}
};
Line_number line_number;
void show_zcat_help() throw()
{
std::printf( "Zcat copies each given file (\"-\" means standard input), to standard\n" );
std::printf( "output. If any given file is compressed, its uncompressed content is\n" );
std::printf( "used. If a given file does not exist, and its name does not end with one\n" );
std::printf( "of the known extensions, zcat tries the compressed file names\n" );
std::printf( "corresponding to the supported compressors. If no files are specified,\n" );
std::printf( "data is read from standard input, decompressed if needed, and sent to\n" );
std::printf( "standard output. Data read from standard input must be of the same type;\n" );
std::printf( "all uncompressed or all compressed with the same compressor.\n" );
std::printf( "The supported compressors are bzip2, gzip, lzip and xz.\n" );
std::printf( "\nUsage: zcat [options] [files]\n" );
std::printf( "\nExit status is 0 if no errors occurred, 1 otherwise.\n" );
std::printf( "\nOptions:\n" );
std::printf( " -h, --help display this help and exit\n" );
std::printf( " -V, --version output version information and exit\n" );
std::printf( " -A, --show-all equivalent to `-vET'\n" );
std::printf( " -b, --number-nonblank number nonblank output lines\n" );
std::printf( " -e equivalent to `-vE'\n" );
std::printf( " -E, --show-ends display `$' at end of each line\n" );
std::printf( " -n, --number number all output lines\n" );
std::printf( " -q, --quiet suppress all messages\n" );
std::printf( " -r, --recursive operate recursively on directories\n" );
std::printf( " -s, --squeeze-blank never more than one single blank line\n" );
std::printf( " -t equivalent to `-vT'\n" );
std::printf( " -T, --show-tabs display TAB characters as `^I'\n" );
std::printf( " -v, --show-nonprinting use `^' and `M-' notation, except for LF and TAB\n" );
std::printf( " --verbose verbose mode (show error messages)\n" );
show_help_addr();
}
int do_cat( const int infd, const int buffer_size,
uint8_t * const inbuf, uint8_t * const outbuf,
const std::string & input_filename,
const Cat_options & cat_options )
{
static int at_bol = 1; // at begin of line. 0 = false, 1 = true,
// 2 = at begin of second blank line.
int inpos = 0; // positions in buffers
int outpos = 0;
int rd = -1; // bytes read by the last readblock
unsigned char c;
while( true )
{
do {
if( outpos >= buffer_size )
{
if( writeblock( STDOUT_FILENO, outbuf, outpos ) != outpos )
{ show_error( "Write error", errno ); return 1; }
outpos = 0;
}
if( inpos > rd ) // inbuf is empty
{
rd = readblock( infd, inbuf, buffer_size );
if( rd != buffer_size && errno )
{
show_error2( "Error reading file", input_filename.c_str() );
return 1;
}
if( rd == 0 )
{
if( writeblock( STDOUT_FILENO, outbuf, outpos ) != outpos )
{ show_error( "Write error", errno ); return 1; }
outpos = 0;
return 0;
}
inpos = 0;
inbuf[rd] = '\n'; // sentinel newline
}
else // a real newline was found
{
if( at_bol > 1 )
{
if( cat_options.squeeze_blank ) { c = inbuf[inpos++]; continue; }
}
else ++at_bol;
if( at_bol > 1 && cat_options.number_lines == 2 )
{
line_number.next();
outpos += line_number.sprint( &outbuf[outpos] );
}
if( cat_options.show_ends ) outbuf[outpos++] = '$';
outbuf[outpos++] = '\n'; // output the newline
}
c = inbuf[inpos++];
}
while( c == '\n' );
if( at_bol > 0 && cat_options.number_lines )
{
line_number.next();
outpos += line_number.sprint( &outbuf[outpos] );
}
at_bol = 0;
// the loops below continue until a newline (real or sentinel) is found
if( cat_options.show_nonprinting )
while( true )
{
if( c < 32 || c >= 127 )
{
if( c == '\n' ) break;
if( c != '\t' || cat_options.show_tabs )
{
if( c >= 128 )
{ c -= 128; outbuf[outpos++] = 'M'; outbuf[outpos++] = '-'; }
if( c < 32 ) { c += 64; outbuf[outpos++] = '^'; }
else if( c == 127 ) { c = '?'; outbuf[outpos++] = '^'; }
}
}
outbuf[outpos++] = c;
c = inbuf[inpos++];
}
else // not quoting
while( c != '\n' )
{
if( c == '\t' && cat_options.show_tabs )
{ c += 64; outbuf[outpos++] = '^'; }
outbuf[outpos++] = c;
c = inbuf[inpos++];
}
}
}
int cat( int infd, const std::string & input_filename,
const Cat_options & cat_options )
{
enum { buffer_size = 4096 };
// buffer with space for sentinel newline at the end
uint8_t * const inbuf = new uint8_t[buffer_size+1];
// buffer with space for character quoting and 255-digit line number
uint8_t * const outbuf = new uint8_t[(4*buffer_size)+256];
pid_t pid = 0;
int retval = 0;
if( !set_data_feeder( &infd, &pid ) ) retval = 1;
else
{
retval = do_cat( infd, buffer_size, inbuf, outbuf,
input_filename, cat_options );
if( pid && wait_for_child( pid, "data feeder" ) != 0 ) retval = 1;
if( close( infd ) != 0 )
{ show_close_error( "data feeder" ); retval = 1; }
}
delete[] inbuf; delete[] outbuf;
return retval;
}
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