1 #!/usr/bin/env python 2 3 """ 4 C library input/output. 5 6 Copyright (C) 2016, 2017 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from __builtins__.stream import filestream 23 from __builtins__.types import check_int, check_string 24 25 import locale 26 27 from native import ( 28 close as _close, 29 fdopen as _fdopen, 30 read as _read, 31 write as _write 32 ) 33 34 # Abstractions for system-level files and streams. 35 36 class sysfile: 37 38 "A system-level file object." 39 40 def __init__(self, fd): 41 42 "Initialise the file with the given 'fd'." 43 44 self.fd = fd 45 46 def read(self, n): 47 48 "Read 'n' bytes from the file, returning a string." 49 50 return read(self.fd, n) 51 52 def write(self, s): 53 54 "Write string 's' to the file." 55 56 return write(self.fd, s) 57 58 def close(self): 59 60 "Close the file." 61 62 close(self.fd) 63 64 class sysstream(filestream): 65 66 "A system-level stream object." 67 68 def __init__(self, fd, mode="r", encoding=None, bufsize=1024): 69 70 """ 71 Initialise the stream with the given 'fd', 'mode', 'encoding' and 72 'bufsize'. 73 """ 74 75 check_int(fd) 76 check_string(mode) 77 78 get_using(filestream.__init__, self)(encoding, bufsize) 79 self.__data__ = _fdopen(fd, mode) 80 81 # Standard streams. 82 83 stdin = sysstream(0) 84 stdout = sysstream(1, "w") 85 stderr = sysstream(2, "w") 86 87 # Localised streams. 88 # Perform locale initialisation explicitly to ensure that the locale module 89 # and various function defaults have been initialised. 90 91 locale.initlocale() 92 lstdin = sysstream(0, "r", locale.getpreferredencoding()) 93 94 # Input/output functions. 95 96 def close(fd): 97 98 "Close the file descriptor 'fd'." 99 100 _close(fd) 101 102 def fdopen(fd, mode="r"): 103 104 """ 105 Open a stream for the given file descriptor 'fd', operating in the given 106 'mode'. 107 """ 108 109 return sysstream(fd, mode) 110 111 def read(fd, n): 112 113 """ 114 Read using the low-level file descriptor 'fd' the given number of bytes 'n'. 115 """ 116 117 check_int(fd) 118 check_int(n) 119 return _read(fd, n) 120 121 def write(fd, s): 122 123 "Write using the low-level file descriptor 'fd' the given string 's'." 124 125 check_int(fd) 126 check_string(s) 127 return _write(fd, s) 128 129 # vim: tabstop=4 expandtab shiftwidth=4
