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a31078bbec
Some folks might think: “you still use RCS”?!? And we will say, hey, at least we switched from SCCS to RCS back in … I think it was around 1994 ... at least we are keeping up! :-) :-) :-) Logs say that SCCS version 18 became RCS version 19 on 1994 March 18. RCS served us well. But now it is time to move on. And so we are switching to git. Calc releases produce a lot of file changes. In the 125 releases of calc since 1996, when I started managing calc releases, there have been 15473 file mods!
131 lines
4.3 KiB
Plaintext
131 lines
4.3 KiB
Plaintext
NAME
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fopen - open a file
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SYNOPSIS
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fopen(filename, mode)
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TYPES
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filename string
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mode string
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return file
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DESCRIPTION
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This function opens the file named filename. A file can be
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opened for either reading, writing, or appending. The mode
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is controlled by the mode flag as follows:
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allow allow file is positioned file(*)
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mode reading writing truncated at mode
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---- ------- ------- --------- --------- ----
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r Y N N beginning text
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rb Y N N beginning binary
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r+ Y N N beginning text
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r+b Y N N beginning binary
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rb+ Y N N beginning binary
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w N Y Y beginning text
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wb N Y Y beginning binary
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w+ Y Y Y beginning text
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w+b Y Y Y beginning binary
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wb+ Y Y Y beginning binary
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a N Y Y end text
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ab N Y Y end binary
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a+ Y Y Y end text
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a+b Y Y Y end binary
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ab+ Y Y Y end binary
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(*) NOTE on 'b' / binary/text mode:
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The 'b' or fopen binary mode has no effect on POSIX / Linux
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/ Un*x-like systems. On those systems a text file is the
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same as a binary file (as it should be for any modern-day
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operating system). Adding 'b' to an fopen has no effect
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and is ignored.
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Some non-POSIX systems sucn as MS Windoz treat text files
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and binary files differently. In text mode MS Windoz consider
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"\r\n" and end-of-line character. On an Apple MAC, the
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text mode end-of-line character is "\r".
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Names of files are subject to ~ expansion just like the C or
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Korn shell. For example, the file name:
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~/lib/gleet
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refers to the file 'gleet' under the directory lib located
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in your home directory. The file name:
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~chongo/was_here
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refers to the a file 'was_here' under the home directory of
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the user 'chongo'.
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If the open is successful, a value of type 'file' will be returned.
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You can use the 'isfile' function to test the return value to see
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if the open succeeded. You should assign the return value of fopen
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to a variable for later use. File values can be copied to more than
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one variable, and using any of the variables with the same file value
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will produce the same results.
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Standard input, standard output and standard error are always opened
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and cannot be closed.
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The truth value of an opened file is TRUE.
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If the open is unsuccessful, the numeric value of errno is returned.
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You can the strerror() builtin to determine what the errno number means.
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EXAMPLE
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; fd = fopen("/etc/motd", "r")
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; print fd
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"/etc/motd"
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; fd
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FILE 3 "/etc/motd" (reading, pos 0)
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; outfile = fopen("~/tmp/output", "w")
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; print outfile
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"~/tmp/output"
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; outfile
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FILE 4 "~/tmp/output" (writing, pos 0)
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; badfile = fopen("not_a_file", "r");
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; if (!isfile(badfile)) {
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;; printf("error(%d): %s\n", errno(badfile), strerror(badfile));
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;; }
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error(2): No such file or directory
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LIMITS
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none
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LINK LIBRARY
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none
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SEE ALSO
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errno, fclose, feof, ferror, fflush, fgetc, fgetline, fgets, files, fopen,
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fprintf, fputc, fputs, fseek, fsize, ftell, isfile, printf, prompt,
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fpathopen, strerror
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## Copyright (C) 1999-2006 Landon Curt Noll
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##
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## Calc is open software; you can redistribute it and/or modify it under
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## the terms of the version 2.1 of the GNU Lesser General Public License
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## as published by the Free Software Foundation.
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##
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## Calc is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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## Public License for more details.
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##
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## A copy of version 2.1 of the GNU Lesser General Public License is
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## distributed with calc under the filename COPYING-LGPL. You should have
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## received a copy with calc; if not, write to Free Software Foundation, Inc.
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## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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##
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## Under source code control: 1994/10/27 03:04:17
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## File existed as early as: 1994
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##
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## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
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## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
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