1 files changed, 59 insertions, 0 deletions
diff --git a/zcatgrep.cc b/zcatgrep.cc
new file mode 100644
index 0000000..31d54e6
--- /dev/null
+++ b/zcatgrep.cc
@@ -0,0 +1,59 @@
+/* Common code for zcat and zgrep
+   Copyright (C) 2010-2021 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 <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+
+int simple_extension_index( const std::string & name )
+  {
+  for( int i = 0; i < num_formats; ++i )
+    {
+    const std::string ext( simple_extensions[i] );
+    if( name.size() > ext.size() &&
+        name.compare( name.size() - ext.size(), ext.size(), ext ) == 0 )
+      return i;
+    }
+  return -1;
+  }
+
+
+int open_instream( std::string & input_filename, const bool search,
+                   const bool no_messages = false )
+  {
+  int infd = open( input_filename.c_str(), O_RDONLY | O_BINARY );
+  if( infd < 0 )
+    {
+    const int saved_errno = errno;
+    if( search && simple_extension_index( input_filename ) < 0 )
+      {
+      for( int i = 0; i < num_formats; ++i )
+        if( enabled_format( format_order[i] ) )
+          {
+          const std::string name( input_filename +
+                                  simple_extensions[format_order[i]] );
+          infd = open( name.c_str(), O_RDONLY | O_BINARY );
+          if( infd >= 0 ) { input_filename = name; break; }
+          }
+      }
+    if( infd < 0 && !no_messages )
+      show_file_error( input_filename.c_str(), "Can't open input file",
+                       saved_errno );
+    }
+  return infd;
+  }