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-rw-r--r--zcat.cc106
1 files changed, 51 insertions, 55 deletions
diff --git a/zcat.cc b/zcat.cc
index 5d400ad..f852c74 100644
--- a/zcat.cc
+++ b/zcat.cc
@@ -1,18 +1,18 @@
-/* Zcat - decompress and concatenate files to standard output
- Copyright (C) 2010-2019 Antonio Diaz Diaz.
+/* Zcat - decompress and concatenate files to standard output
+ Copyright (C) 2010-2020 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 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.
+ 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/>.
+ 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
@@ -90,19 +90,21 @@ Line_number line_number;
void show_help()
{
- std::printf( "Zcat copies each given file to standard output. If any given file is\n"
- "compressed, its decompressed content is used. If a given file does not\n"
- "exist, and its name does not end with one of the known extensions, zcat\n"
- "tries the compressed file names corresponding to the formats supported.\n"
+ std::printf( "zcat copies each file argument to standard output in sequence. If any\n"
+ "file given is compressed, its decompressed content is copied. If a file\n"
+ "given does not exist, and its name does not end with one of the known\n"
+ "extensions, zcat tries the compressed file names corresponding to the\n"
+ "formats supported. If a file fails to decompress, zcat continues copying the\n"
+ "rest of the files.\n"
"\nIf a file is specified as '-', data are read from standard input,\n"
"decompressed if needed, and sent to standard output. Data read from\n"
"standard input must be of the same type; all uncompressed or all in the\n"
- "same compression format.\n"
+ "same compressed format.\n"
"\nIf no files are specified, recursive searches examine the current\n"
"working directory, and nonrecursive searches read standard input.\n"
- "\nThe formats supported are bzip2, gzip, lzip and xz.\n"
+ "\nThe formats supported are bzip2, gzip, lzip, and xz.\n"
"\nUsage: zcat [options] [files]\n"
- "\nExit status is 0 if no errors occurred, non-zero otherwise.\n"
+ "\nExit status is 0 if no errors occurred, 1 otherwise.\n"
"\nOptions:\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
@@ -113,7 +115,7 @@ void show_help()
" -M, --format=<list> process only the formats in <list>\n"
" -n, --number number all output lines\n"
" -N, --no-rcfile don't read runtime configuration file\n"
- " -O, --force-format=<fmt> force given format (bz2, gz, lz, xz)\n"
+ " -O, --force-format=<fmt> force the format given (bz2, gz, lz, xz)\n"
" -q, --quiet suppress all messages\n"
" -r, --recursive operate recursively on directories\n"
" -R, --dereference-recursive recursively follow symbolic links\n"
@@ -130,10 +132,10 @@ void show_help()
}
-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 )
+bool 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.
@@ -148,7 +150,7 @@ int do_cat( const int infd, const int buffer_size,
if( outpos >= buffer_size )
{
if( writeblock( STDOUT_FILENO, outbuf, outpos ) != outpos )
- { show_error( "Write error", errno ); return 1; }
+ { show_error( "Write error", errno ); return false; }
outpos = 0;
}
if( inpos > rd ) // inbuf is empty
@@ -157,14 +159,14 @@ int do_cat( const int infd, const int buffer_size,
if( rd != buffer_size && errno )
{
show_file_error( input_filename.c_str(), "Read error", errno );
- return 1;
+ return false;
}
if( rd == 0 )
{
if( writeblock( STDOUT_FILENO, outbuf, outpos ) != outpos )
- { show_error( "Write error", errno ); return 1; }
+ { show_error( "Write error", errno ); return false; }
outpos = 0;
- return 0;
+ return true;
}
inpos = 0;
inbuf[rd] = '\n'; // sentinel newline
@@ -226,32 +228,27 @@ int do_cat( const int infd, const int buffer_size,
}
-int cat( int infd, const int format_index, const std::string & input_filename,
- const Cat_options & cat_options )
+bool cat( int infd, const int format_index, const std::string & input_filename,
+ const Cat_options & cat_options )
{
enum { buffer_size = 4096, outbuf_size = (5 * buffer_size) + 256 + 1 };
- // buffer with space for sentinel newline at the end
+ // input 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, 255-digit line number,
+ // output buffer with space for character quoting, 255-digit line number,
// worst case flushing respect to inbuf, and a canary byte.
uint8_t * const outbuf = new uint8_t[outbuf_size];
outbuf[outbuf_size-1] = 0;
- int retval = 0;
Children children;
- if( !set_data_feeder( input_filename, &infd, children, format_index ) )
- retval = 1;
- else
- retval = do_cat( infd, buffer_size, inbuf, outbuf,
- input_filename, cat_options );
-
- if( !good_status( children, retval == 0 ) ) retval = 1;
-
- if( retval == 0 && close( infd ) != 0 )
- { show_close_error(); retval = 1; }
- if( outbuf[outbuf_size-1] != 0 )
- internal_error( "buffer overflow." );
+ bool error = false;
+
+ if( !set_data_feeder( input_filename, &infd, children, format_index ) ||
+ !do_cat( infd, buffer_size, inbuf, outbuf, input_filename, cat_options ) )
+ error = true;
+ if( !good_status( children, !error ) ) error = true;
+ if( !error && close( infd ) != 0 ) { show_close_error(); error = true; }
+ if( outbuf[outbuf_size-1] != 0 ) internal_error( "buffer overflow." );
delete[] outbuf; delete[] inbuf;
- return retval;
+ return !error;
}
} // end namespace
@@ -264,8 +261,8 @@ int main( const int argc, const char * const argv[] )
int recursive = 0; // 1 = '-r', 2 = '-R'
std::list< std::string > filenames;
Cat_options cat_options;
- invocation_name = argv[0];
program_name = "zcat";
+ invocation_name = ( argc > 0 ) ? argv[0] : program_name;
const Arg_parser::Option options[] =
{
@@ -357,16 +354,15 @@ int main( const int argc, const char * const argv[] )
if( filenames.empty() ) filenames.push_back( recursive ? "." : "-" );
std::string input_filename;
- int retval = 0;
bool error = false;
bool stdin_used = false;
while( next_filename( filenames, input_filename, error, recursive ) )
{
int infd;
- if( input_filename.empty() )
+ if( input_filename == "." )
{
if( stdin_used ) continue; else stdin_used = true;
- infd = STDIN_FILENO;
+ infd = STDIN_FILENO; input_filename = "-";
}
else
{
@@ -374,10 +370,11 @@ int main( const int argc, const char * const argv[] )
if( infd < 0 ) { error = true; continue; }
}
- const int tmp = cat( infd, format_index, input_filename, cat_options );
- if( tmp > retval ) retval = tmp;
+ if( !cat( infd, format_index, input_filename, cat_options ) ) error = true;
- if( input_filename.size() ) close( infd );
+ if( close( infd ) != 0 )
+ { show_file_error( input_filename.c_str(), "Error closing input file",
+ errno ); error = true; }
}
if( std::fclose( stdout ) != 0 )
@@ -385,6 +382,5 @@ int main( const int argc, const char * const argv[] )
show_error( "Error closing stdout", errno );
error = true;
}
- if( error && retval == 0 ) retval = 1;
- return retval;
+ return error;
}