1 /* 2 * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers. 3 * All rights reserved. 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 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. 13 */ 14 15 #pragma ident "%Z%%M% %I% %E% SMI" 16 17 #include <sm/gen.h> 18 SM_RCSID("@(#)$Id: fget.c,v 1.22 2001/08/27 18:54:14 gshapiro Exp $") 19 #include <stdlib.h> 20 #include <string.h> 21 #include <sm/io.h> 22 #include <sm/assert.h> 23 #include "local.h" 24 25 /* 26 ** SM_IO_FGETS -- get a string from a file 27 ** 28 ** Read at most n-1 characters from the given file. 29 ** Stop when a newline has been read, or the count ('n') runs out. 30 ** 31 ** Parameters: 32 ** fp -- the file to read from 33 ** timeout -- time to complete reading the string in milliseconds 34 ** buf -- buffer to place read string in 35 ** n -- size of 'buf' 36 ** 37 ** Returns: 38 ** success: returns value of 'buf' 39 ** failure: NULL (no characters were read) 40 ** timeout: NULL and errno set to EAGAIN 41 ** 42 ** Side Effects: 43 ** may move the file pointer 44 */ 45 46 char * 47 sm_io_fgets(fp, timeout, buf, n) 48 register SM_FILE_T *fp; 49 int timeout; 50 char *buf; 51 register int n; 52 { 53 register int len; 54 register char *s; 55 register unsigned char *p, *t; 56 57 SM_REQUIRE_ISA(fp, SmFileMagic); 58 if (n <= 0) /* sanity check */ 59 return NULL; 60 61 s = buf; 62 n--; /* leave space for NUL */ 63 while (n > 0) 64 { 65 /* If the buffer is empty, refill it. */ 66 if ((len = fp->f_r) <= 0) 67 { 68 69 /* 70 ** Timeout is only passed if we can't get the data 71 ** from the buffer (which is counted as immediately). 72 */ 73 74 if (sm_refill(fp, timeout) != 0) 75 { 76 /* EOF/error: stop with partial or no line */ 77 if (s == buf) 78 return NULL; 79 break; 80 } 81 len = fp->f_r; 82 } 83 p = fp->f_p; 84 85 /* 86 ** Scan through at most n bytes of the current buffer, 87 ** looking for '\n'. If found, copy up to and including 88 ** newline, and stop. Otherwise, copy entire chunk 89 ** and loop. 90 */ 91 92 if (len > n) 93 len = n; 94 t = (unsigned char *) memchr((void *) p, '\n', len); 95 if (t != NULL) 96 { 97 len = ++t - p; 98 fp->f_r -= len; 99 fp->f_p = t; 100 (void) memcpy((void *) s, (void *) p, len); 101 s[len] = 0; 102 return buf; 103 } 104 fp->f_r -= len; 105 fp->f_p += len; 106 (void) memcpy((void *) s, (void *) p, len); 107 s += len; 108 n -= len; 109 } 110 *s = 0; 111 return buf; 112 } 113