Mercurial > jwe > octave
view libinterp/corefcn/ls-ascii-helper.cc @ 31170:06c76eca5f95 default tip @
maint: merge stable to default
author | John W. Eaton <jwe@octave.org> |
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date | Fri, 29 Jul 2022 12:02:42 -0400 |
parents | 796f54d4ddbf |
children |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 2009-2022 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // 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 // <https://www.gnu.org/licenses/>. // //////////////////////////////////////////////////////////////////////// #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include "ls-ascii-helper.h" #include <istream> #include <sstream> OCTAVE_NAMESPACE_BEGIN // Helper functions when reading from ascii files. // These functions take care of different line endings (LF, CR, CRLF) // when files were opened in text mode for writing and are now opened in // binary mode for reading. // Even though we no longer store files in text mode, keep this logic // to allow loading older files that might have CRLF or CR line endings. // 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 character 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 characters 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::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 character peeked, so read it, store it, and // proceed to next. char d; is.get (d); buf << d; } } return buf.str (); } OCTAVE_NAMESPACE_END