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Member "alsa-oss-1.1.8/alsa/stdioemu.c" (7 Jan 2019, 3049 Bytes) of package /linux/misc/alsa-oss-1.1.8.tar.bz2:

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    1 /*
    2 
    3     Copyright (C) 2000 Stefan Westerfeld
    4                        stefan@space.twc.de
    5 
    6     This library is free software; you can redistribute it and/or
    7     modify it under the terms of the GNU Library General Public
    8     License as published by the Free Software Foundation; either
    9     version 2 of the License, or (at your option) any later version.
   10   
   11     This library is distributed in the hope that it will be useful,
   12     but WITHOUT ANY WARRANTY; without even the implied warranty of
   13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   14     Library General Public License for more details.
   15    
   16     You should have received a copy of the GNU Library General Public License
   17     along with this library; see the file COPYING.LIB.  If not, write to
   18     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   19     Boston, MA  02110-1301, USA
   20 
   21     Modified to add support for 64 bit fopen by Mike Hearn <mike@navi.cx>
   22 */
   23 
   24 /*
   25  * This source only exists because some very special programs think that
   26  * it is a very special idea to access /dev/dsp by the means of stdio, so
   27  * we need to fake FILE* access for artsdsp as well.
   28  *
   29  * To do so, it relies on glibc internals, so that it will probably not work
   30  * on other systems - but then again, it might not be necessary on other
   31  * systems, when fopen properly calls open, it might as well work unchanged.
   32  */
   33 
   34 
   35 #ifndef _GNU_SOURCE
   36 #define _GNU_SOURCE
   37 #endif
   38 
   39 #include <stdio.h>
   40 
   41 struct fd_cookie {
   42     int fd;
   43 };
   44 
   45 static ssize_t fdc_read (void *cookie, char *buffer, size_t size)
   46 {
   47     struct fd_cookie *fdc = (struct fd_cookie *)cookie;
   48     return read(fdc->fd, buffer, size);
   49 }
   50 
   51 static ssize_t fdc_write (void *cookie, const char *buffer, size_t size)
   52 {
   53     struct fd_cookie *fdc = (struct fd_cookie *)cookie;
   54     return write(fdc->fd, buffer, size);
   55 }
   56 
   57 static int fdc_seek (void* cookie ATTRIBUTE_UNUSED,
   58              off64_t* position ATTRIBUTE_UNUSED,
   59              int whence ATTRIBUTE_UNUSED)
   60 {
   61     return -1;
   62 }
   63 
   64 static int fdc_clean (void *cookie)
   65 {
   66     struct fd_cookie *fdc = (struct fd_cookie *)cookie;
   67     int result = close(fdc->fd);
   68     free(cookie);
   69     return result;
   70 }
   71 
   72 static FILE *fake_fopen(const char *path, const char *mode, int flags)
   73 {
   74     cookie_io_functions_t fns = { fdc_read, fdc_write, fdc_seek, fdc_clean };
   75     struct fd_cookie *fdc = (struct fd_cookie *)malloc(sizeof(struct fd_cookie));
   76     const char *mptr;
   77     int open_mode = 0;
   78     FILE *result = 0;
   79 
   80     for(mptr = mode; *mptr; mptr++) {
   81         if(*mptr == 'r') open_mode |= 1; /* 1 = read */
   82         if(*mptr == 'w') open_mode |= 2; /* 2 = write */
   83         if(*mptr == '+') open_mode |= 3; /* 3 = readwrite */
   84         if(*mptr == 'a') open_mode |= 2; /* append -> write */
   85     }
   86 
   87     switch (open_mode) {
   88     case 1:
   89         fdc->fd = open(path, O_RDONLY | flags, 0666);
   90         break;
   91     case 2:
   92         fdc->fd = open(path, O_WRONLY | flags, 0666);
   93         break;
   94     default:
   95         fdc->fd = open(path, O_RDWR | flags, 0666);
   96         break;
   97     }
   98 
   99     if (open_mode && fdc->fd > 0) {
  100         result = fopencookie (fdc,"w", fns);
  101         result->_fileno = fdc->fd;      /* ugly patchy slimy kludgy hack */
  102     }
  103     return result;
  104 }