1 // sg_file.cxx -- File I/O routines
3 // Written by Curtis Olson, started November 1999.
5 // Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 #include <simgear/compiler.h>
34 #include <sys/types.h>
38 #if !defined(_MSC_VER)
42 #include <simgear/misc/stdint.hxx>
43 #include <simgear/debug/logstream.hxx>
45 #include "sg_file.hxx"
49 SGFile::SGFile(const string &file, int repeat_)
50 : file_name(file), fp(-1), eof_flag(true), repeat(repeat_), iteration(0)
52 set_type( sgFileType );
55 SGFile::SGFile( int existingFd ) :
61 set_type( sgFileType );
68 // open the file based on specified direction
69 bool SGFile::open( const SGProtocolDir d ) {
72 if ( get_dir() == SG_IO_OUT ) {
76 mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
78 fp = ::open( file_name.c_str(), O_WRONLY | O_CREAT | O_TRUNC, mode );
79 } else if ( get_dir() == SG_IO_IN ) {
80 fp = ::open( file_name.c_str(), O_RDONLY );
82 SG_LOG( SG_IO, SG_ALERT,
83 "Error: bidirection mode not available for files." );
88 SG_LOG( SG_IO, SG_ALERT, "Error opening file: " << file_name );
97 // read a block of data of specified size
98 int SGFile::read( char *buf, int length ) {
100 ssize_t result = ::read( fp, buf, length );
101 if ( length > 0 && result == 0 ) {
102 if (repeat < 0 || iteration < repeat - 1) {
104 // loop reading the file, unless it is empty
105 off_t fileLen = ::lseek(fp, 0, SEEK_CUR);
110 ::lseek(fp, 0, SEEK_SET);
111 return ::read(fp, buf, length);
121 // read a line of data, length is max size of input buffer
122 int SGFile::readline( char *buf, int length ) {
123 // save our current position
124 int pos = lseek( fp, 0, SEEK_CUR );
127 ssize_t result = ::read( fp, buf, length );
128 if ( length > 0 && result == 0 ) {
129 if ((repeat < 0 || iteration < repeat - 1) && pos != 0) {
131 pos = ::lseek(fp, 0, SEEK_SET);
132 result = ::read(fp, buf, length);
138 // find the end of line and reset position
140 for ( i = 0; i < result && buf[i] != '\n'; ++i );
141 if ( buf[i] == '\n' ) {
146 lseek( fp, pos + result, SEEK_SET );
149 buf[ result ] = '\0';
155 // write data to a file
156 int SGFile::write( const char *buf, const int length ) {
157 int result = ::write( fp, buf, length );
158 if ( result != length ) {
159 SG_LOG( SG_IO, SG_ALERT, "Error writing data: " << file_name );
166 // write null terminated string to a file
167 int SGFile::writestring( const char *str ) {
168 int length = std::strlen( str );
169 return write( str, length );
174 bool SGFile::close() {
175 if ( ::close( fp ) == -1 ) {