Mercurial > hg > octave-nkf
diff src/ls-ascii-helper.cc @ 8946:e7e928088e90
fix CRLF issues with text-mode reading in windows when loading ascii data
author | Benjamin Lindner <lindnerb@users.sourceforge.net> |
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date | Tue, 10 Mar 2009 01:01:50 -0400 |
parents | |
children | cd96d29c5efa |
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new file mode 100644 --- /dev/null +++ b/src/ls-ascii-helper.cc @@ -0,0 +1,181 @@ +/* + +Copyright (C) 2009 Benjamin Lindner + +This file is part of Octave. + +Octave 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. + +Octave 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 Octave; see the file COPYING. If not, see +<http://www.gnu.org/licenses/>. + +*/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "ls-ascii-helper.h" + +#include <iostream> +#include <sstream> + +// Helper functions when reading from ascii files. + +// These function take care of CR/LF issues when files are opened in +// text-mode for reading. + +// Skip characters from stream IS until a newline is reached. +// Depending on KEEP_NEWLINE, either eat newline from stream or +// keep it unread. + +void +skip_until_newline (std::istream& is, bool keep_newline) +{ + if (! is) + return; + + while (is) + { + char c = is.peek (); + + if (c == '\n' || c == '\r') + { + // Reached newline. + if (! keep_newline) + { + // Eat the CR or LF character. + char d; + is.get (d); + + // Make sure that for binary-mode opened ascii files + // containing CRLF line endings we skip the LF after CR. + if (c == '\r' && is.peek () == '\n') + { + // Yes, LF following CR, eat it. + is.get (d); + } + } + + // Newline was found, and read from stream if + // keep_newline == true, so exit loop. + break; + } + else + { + // No newline charater peeked, so read it and proceed to next + // character. + char d; + is.get (d); + } + } +} + + +// If stream IS currently points to a newline (a leftover from a +// previous read) then eat newline(s) until a non-newline character is +// found. + +void +skip_preceeding_newline (std::istream& is) +{ + if (! is) + return; + + // Check whether IS currently points to newline character. + char c = is.peek (); + + if (c == '\n' || c == '\r') + { + // Yes, at newline. + do + { + // Eat the CR or LF character. + char d; + is.get (d); + + // Make sure that for binary-mode opened ascii files + // containing CRLF line endings we skip the LF after CR. + if (c == '\r' && is.peek () == '\n') + { + // Yes, LF following CR, eat it. + is.get (d); + } + + // Peek into next character. + c = is.peek (); + + // Loop while still a newline ahead. + } + while (c == '\n' || c == '\r'); + } +} + +// Read charaters from stream IS until a newline is reached. +// Depending on KEEP_NEWLINE, either eat newline from stream or keep +// it unread. Characters read are stored and returned as +// std::string. + +std::string +read_until_newline (std::istream& is, bool keep_newline) +{ + if (! is) + return std::string (); + + std::ostringstream buf; + + while (is) + { + char c = is.peek (); + + if (c == '\n' || c == '\r') + { + // Reached newline. + if (! keep_newline) + { + // Eat the CR or LF character. + char d; + is.get (d); + + // Make sure that for binary-mode opened ascii files + // containing CRLF line endings we skip the LF after + // CR. + + if (c == '\r' && is.peek () == '\n') + { + // Yes, LF following CR, eat it. + is.get (d); + } + } + + // Newline was found, and read from stream if + // keep_newline == true, so exit loop. + break; + } + else + { + // No newline charater peeked, so read it, store it, and + // proceed to next. + char d; + is.get (d); + buf << d; + } + } + + return buf.str (); +} + +/* +;;; Local Variables: *** +;;; mode: C++ *** +;;; End: *** +*/