needs -I/sys for the miscfs directory, put the man pages in

[unix-history] / usr / src / lib / libc / stdio / findfp.c

diff --git a/usr/src/lib/libc/stdio/findfp.c b/usr/src/lib/libc/stdio/findfp.c
index 33b943c..d5172de 100644 (file)
--- a/usr/src/lib/libc/stdio/findfp.c
+++ b/usr/src/lib/libc/stdio/findfp.c
@@ -1,122 +1,137 @@
-/*
- * Copyright (c) 1983, 1985 Regents of the University of California.
- * All rights reserved.  The Berkeley software License Agreement
- * specifies the terms and conditions for redistribution.
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * %sccs.include.redist.c%

  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)

-static char sccsid[] = "@(#)findfp.c   5.7 (Berkeley) %G%";
-#endif LIBC_SCCS and not lint
+static char sccsid[] = "@(#)findfp.c   5.10 (Berkeley) %G%";
+#endif /* LIBC_SCCS and not lint */

 
 

+#include <unistd.h>

 #include <stdio.h>
 #include <errno.h>
 #include <stdio.h>
 #include <errno.h>

+#include <stdlib.h>
+#include <string.h>
+#include "local.h"
+#include "glue.h"

 
 

-extern int errno;
-
-#define active(iop)    ((iop)->_flag & (_IOREAD|_IOWRT|_IORW))
+int    __sdidinit;

 
 #define NSTATIC        20      /* stdin + stdout + stderr + the usual */
 
 #define NSTATIC        20      /* stdin + stdout + stderr + the usual */

+#define        NDYNAMIC 10     /* add ten more whenever necessary */

 
 

-FILE _iob[NSTATIC] = {
-       { 0, NULL, NULL, 0, _IOREAD,            0 },    /* stdin  */
-       { 0, NULL, NULL, 0, _IOWRT,             1 },    /* stdout */
-       { 0, NULL, NULL, 0, _IOWRT|_IONBF,      2 },    /* stderr */
-};
+#define        std(flags, file) \
+       {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite}
+/*      p r w flags file _bf z  cookie      close    read    seek    write */
+
+static FILE usual[NSTATIC - 3];        /* the usual */
+static struct glue uglue = { 0, NSTATIC - 3, usual };

 
 

-extern char    *calloc();
+FILE __sF[3] = {
+       std(__SRD, STDIN_FILENO),               /* stdin */
+       std(__SWR, STDOUT_FILENO),              /* stdout */
+       std(__SWR|__SNBF, STDERR_FILENO)        /* stderr */
+};
+struct glue __sglue = { &uglue, 3, __sF };

 
 

-static char sbuf[NSTATIC];
-char   *_smallbuf = sbuf;
-static FILE    **iobglue;
-static FILE    **endglue;
+static struct glue *
+moreglue(n)
+       register int n;
+{
+       register struct glue *g;
+       register FILE *p;
+       static FILE empty;
+
+       g = (struct glue *)malloc(sizeof(*g) + n * sizeof(FILE));
+       if (g == NULL)
+               return (NULL);
+       p = (FILE *)(g + 1);
+       g->next = NULL;
+       g->niobs = n;
+       g->iobs = p;
+       while (--n >= 0)
+               *p++ = empty;
+       return (g);
+}

 
 /*
  * Find a free FILE for fopen et al.
 
 /*
  * Find a free FILE for fopen et al.

- * We have a fixed static array of entries, and in addition
- * may allocate additional entries dynamically, up to the kernel
- * limit on the number of open files.
- * At first just check for a free slot in the fixed static array.
- * If none are available, then we allocate a structure to glue together
- * the old and new FILE entries, which are then no longer contiguous.

  */
 FILE *
  */
 FILE *

-_findiop()
+__sfp()

 {
 {

-       register FILE **iov, *iop;

        register FILE *fp;
        register FILE *fp;

-
-       if (iobglue == 0) {
-               for (iop = _iob; iop < _iob + NSTATIC; iop++)
-                       if (!active(iop))
-                               return (iop);
-
-               if (_f_morefiles() == 0) {
-                       errno = ENOMEM;
-                       return (NULL);
-               }
+       register int n;
+       register struct glue *g;
+
+       if (!__sdidinit)
+               __sinit();
+       for (g = &__sglue;; g = g->next) {
+               for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
+                       if (fp->_flags == 0)
+                               goto found;
+               if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
+                       break;

        }
        }

-
-       iov = iobglue;
-       while (*iov != NULL && active(*iov))
-               if (++iov >= endglue) {
-                       errno = EMFILE;
-                       return (NULL);
-               }
-
-       if (*iov == NULL)
-               *iov = (FILE *)calloc(1, sizeof **iov);
-
-       return (*iov);
+       return (NULL);
+found:
+       fp->_flags = 1;         /* reserve this slot; caller sets real flags */
+       fp->_p = NULL;          /* no current pointer */
+       fp->_w = 0;             /* nothing to read or write */
+       fp->_r = 0;
+       fp->_bf._base = NULL;   /* no buffer */
+       fp->_bf._size = 0;
+       fp->_lbfsize = 0;       /* not line buffered */
+       fp->_file = -1;         /* no file */
+/*     fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
+       fp->_ub._base = NULL;   /* no ungetc buffer */
+       fp->_ub._size = 0;
+       fp->_lb._base = NULL;   /* no line buffer */
+       fp->_lb._size = 0;
+       return (fp);

 }
 
 }
 

-_f_morefiles()
+/*
+ * XXX.  Force immediate allocation of internal memory.  Not used by stdio,
+ * but documented historically for certain applications.  Bad applications.
+ */
+f_prealloc()

 {
 {

-       register FILE **iov;
-       register FILE *fp;
-       register char *cp;
-       int nfiles;
+       int n = getdtablesize() - NSTATIC + 20;         /* 20 for slop */
+       register struct glue *g;

 
 

-       nfiles = getdtablesize();
-
-       iobglue = (FILE **)calloc(nfiles, sizeof *iobglue);
-       if (iobglue == NULL)
-               return (0);
-
-       endglue = iobglue + nfiles;
-
-       for (fp = _iob, iov = iobglue; fp < &_iob[NSTATIC]; /* void */)
-               *iov++ = fp++;
-
-       _smallbuf = calloc(nfiles, sizeof(*_smallbuf));
-       return (1);
+       for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
+               /* void */;
+       if (n > 0)
+               g->next = moreglue(n);

 }
 
 }
 

-f_prealloc()
+/*
+ * exit() calls _cleanup() through *__cleanup, set whenever we
+ * open or buffer a file.  This chicanery is done so that programs
+ * that do not use stdio need not link it all in.
+ *
+ * The name `_cleanup' is, alas, fairly well known outside stdio.
+ */
+void
+_cleanup()

 {
 {

-       register FILE **iov;
-       register FILE *fp;
-
-       if (iobglue == NULL && _f_morefiles() == 0)
-               return;
-
-       for (iov = iobglue; iov < endglue; iov++)
-               if (*iov == NULL)
-                       *iov = (FILE *)calloc(1, sizeof **iov);
+       /* (void) _fwalk(fclose); */
+       (void) _fwalk(__sflush);                /* `cheating' */

 }
 
 }
 

-_fwalk(function)
-       register int (*function)();
+/*
+ * __sinit() is called whenever stdio's internal variables must be set up.
+ */
+void
+__sinit()

 {
 {

-       register FILE **iov;
-       register FILE *fp;
-
-       if (iobglue == NULL) {
-               for (fp = _iob; fp < &_iob[NSTATIC]; fp++)
-                       if (active(fp))
-                               (*function)(fp);
-       } else {
-               for (iov = iobglue; iov < endglue; iov++)
-                       if (*iov && active(*iov))
-                               (*function)(*iov);
-       }
+       /* make sure we clean up on exit */
+       __cleanup = _cleanup;           /* conservative */
+       __sdidinit = 1;

 }
 }