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Annotation of prex-old/usr/lib/libc/stdio/findfp.c, Revision 1.1.1.1

1.1       nbrk        1: /*-
                      2:  * Copyright (c) 1990, 1993
                      3:  *     The Regents of the University of California.  All rights reserved.
                      4:  *
                      5:  * This code is derived from software contributed to Berkeley by
                      6:  * Chris Torek.
                      7:  *
                      8:  * Redistribution and use in source and binary forms, with or without
                      9:  * modification, are permitted provided that the following conditions
                     10:  * are met:
                     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. Redistributions in binary form must reproduce the above copyright
                     14:  *    notice, this list of conditions and the following disclaimer in the
                     15:  *    documentation and/or other materials provided with the distribution.
                     16:  * 3. Neither the name of the University nor the names of its contributors
                     17:  *    may be used to endorse or promote products derived from this software
                     18:  *    without specific prior written permission.
                     19:  *
                     20:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     21:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     22:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     23:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     24:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     25:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     26:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     27:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     28:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     29:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     30:  * SUCH DAMAGE.
                     31:  */
                     32:
                     33: #include <sys/param.h>
                     34: #include <unistd.h>
                     35: #include <stdio.h>
                     36: #include <stdlib.h>
                     37: #include <errno.h>
                     38: #include <string.h>
                     39: #include "local.h"
                     40:
                     41: int    __sdidinit;
                     42:
                     43: #define        std(next, flags, file) \
                     44:        {next,NULL,0,0,flags,file,{0,0},{0,0},NULL,0,{0},{0}}
                     45: /*      p r w flags file _bf z */
                     46:
                     47: FILE __sF[3] = {
                     48:        std(&__sF[1], __SRD, STDIN_FILENO),
                     49:        std(&__sF[2], __SWR, STDOUT_FILENO),
                     50:        std(NULL, __SWR|__SNBF, STDERR_FILENO)
                     51: };
                     52:
                     53: /*
                     54:  * Find a free FILE for fopen et al.
                     55:  */
                     56: FILE *
                     57: __sfp()
                     58: {
                     59:        FILE *fp, *tmp;
                     60:
                     61:        if (!__sdidinit)
                     62:                __sinit();
                     63:        for (fp = &__sF[0];; fp = fp->next) {
                     64:                if (fp->_flags == 0)
                     65:                        goto found;
                     66:                if (fp->next == NULL) {
                     67:                        if ((tmp = malloc(sizeof(FILE))) == NULL)
                     68:                                break;
                     69:                        tmp->next = NULL;
                     70:                        fp->next = tmp;
                     71:                        fp = tmp;
                     72:                        goto found;
                     73:                }
                     74:        }
                     75:        return (NULL);
                     76: found:
                     77:        fp->_flags = 1;         /* reserve this slot; caller sets real flags */
                     78:        fp->_p = NULL;          /* no current pointer */
                     79:        fp->_w = 0;             /* nothing to read or write */
                     80:        fp->_r = 0;
                     81:        fp->_bf._base = NULL;   /* no buffer */
                     82:        fp->_bf._size = 0;
                     83:        fp->_file = -1;         /* no file */
                     84:        fp->_ub._base = NULL;   /* no ungetc buffer */
                     85:        fp->_ub._size = 0;
                     86:        return (fp);
                     87: }
                     88:
                     89: /*
                     90:  * exit() calls _cleanup() through *__cleanup, set whenever we
                     91:  * open or buffer a file.  This chicanery is done so that programs
                     92:  * that do not use stdio need not link it all in.
                     93:  *
                     94:  * The name `_cleanup' is, alas, fairly well known outside stdio.
                     95: b */
                     96: void
                     97: _cleanup()
                     98: {
                     99:        /* (void) _fwalk(fclose); */
                    100:        (void) _fwalk(__sflush);                /* `cheating' */
                    101: }
                    102:
                    103: /*
                    104:  * __sinit() is called whenever stdio's internal variables must be set up.
                    105:  */
                    106: void
                    107: __sinit()
                    108: {
                    109:        /* make sure we clean up on exit */
                    110:        __cleanup = _cleanup;           /* conservative */
                    111:        __sdidinit = 1;
                    112: }