2 * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
10 * By using this file, you agree to the terms and conditions set
11 * forth in the LICENSE file which can be found at the top level of
12 * the sendmail distribution.
16 SM_RCSID("@(#)$Id: makebuf.c,v 1.26 2001/10/31 16:04:08 ca Exp $")
19 #include <sys/types.h>
27 ** SM_MAKEBUF -- make a buffer for the file
30 ** fp -- the file to be buffered
35 ** Allocate a file buffer, or switch to unbuffered I/O.
36 ** By default tty devices default to line buffered.
41 register SM_FILE_T *fp;
48 if (fp->f_flags & SMNBF)
50 fp->f_bf.smb_base = fp->f_p = fp->f_nbuf;
51 fp->f_bf.smb_size = 1;
54 flags = sm_whatbuf(fp, &size, &couldbetty);
55 if ((p = sm_malloc(size)) == NULL)
58 fp->f_bf.smb_base = fp->f_p = fp->f_nbuf;
59 fp->f_bf.smb_size = 1;
65 fp->f_bf.smb_base = fp->f_p = p;
66 fp->f_bf.smb_size = size;
67 if (couldbetty && isatty(fp->f_file))
73 ** SM_WHATBUF -- determine proper buffer for a file (internal)
75 ** Plus it fills in 'bufsize' for recommended buffer size and
76 ** fills in flag to indicate if 'fp' could be a tty (nothing
77 ** to do with "betty" :-) ).
80 ** fp -- file pointer to be buffered
81 ** bufsize -- new buffer size (a return)
82 ** couldbetty -- could be a tty (returns)
87 ** SMNPT -- not seek opimized
88 ** SMOPT -- seek opimized
92 sm_whatbuf(fp, bufsize, couldbetty)
93 register SM_FILE_T *fp;
99 if (fp->f_file < 0 || fstat(fp->f_file, &st) < 0)
102 *bufsize = SM_IO_BUFSIZ;
106 /* could be a tty iff it is a character device */
107 *couldbetty = S_ISCHR(st.st_mode);
108 if (st.st_blksize == 0)
110 *bufsize = SM_IO_BUFSIZ;
114 #if SM_IO_MAX_BUF_FILE > 0
115 if (S_ISREG(st.st_mode) && st.st_blksize > SM_IO_MAX_BUF_FILE)
116 st.st_blksize = SM_IO_MAX_BUF_FILE;
117 #endif /* SM_IO_MAX_BUF_FILE > 0 */
119 #if SM_IO_MAX_BUF > 0 || SM_IO_MIN_BUF > 0
120 if (!S_ISREG(st.st_mode))
122 # if SM_IO_MAX_BUF > 0
123 if (st.st_blksize > SM_IO_MAX_BUF)
124 st.st_blksize = SM_IO_MAX_BUF;
125 # if SM_IO_MIN_BUF > 0
127 # endif /* SM_IO_MIN_BUF > 0 */
128 # endif /* SM_IO_MAX_BUF > 0 */
129 # if SM_IO_MIN_BUF > 0
130 if (st.st_blksize < SM_IO_MIN_BUF)
131 st.st_blksize = SM_IO_MIN_BUF;
132 # endif /* SM_IO_MIN_BUF > 0 */
134 #endif /* SM_IO_MAX_BUF > 0 || SM_IO_MIN_BUF > 0 */
137 ** Optimise fseek() only if it is a regular file. (The test for
138 ** sm_std_seek is mainly paranoia.) It is safe to set _blksize
139 ** unconditionally; it will only be used if SMOPT is also set.
142 if ((fp->f_flags & SMSTR) == 0)
144 *bufsize = st.st_blksize;
145 fp->f_blksize = st.st_blksize;
148 *bufsize = SM_IO_BUFSIZ;
149 if ((st.st_mode & S_IFMT) == S_IFREG &&
150 fp->f_seek == sm_stdseek)