usr/src/cmd/sgs/libconv/common/strproc.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28 /*
  29  * General purpse string manipulation routines
  30  */
  31
  32 #include        <stdio.h>
  33 #include        <_conv.h>
  34
  35
  36 /*
  37  * Implementation of isspace() that does not require <ctype.h>
  38  * or <sys/ctype.h>, appropriate for simple non-localized use.
  39  */
  40 int
  41 conv_strproc_isspace(int c)
  42 {
  43         return ((c == ' ') || (c == '\t') || (c == '\r') || (c == '\n'));
  44 }
  45
  46 /*
  47  * Remove leading and trailing whitespace from the given string.
  48  *
  49  * entry:
  50  *      str - String to be trimmed
  51  *
  52  * exit:
  53  *      The pointer to the trimmed string is returned.
  54  *
  55  * note:
  56  *      Leading whitespace is trimmed by advancing the given str pointer,
  57  *      and not by making a copy or allocing more memory. Hence, the caller
  58  *      should retain a copy of the original str pointer if they need to
  59  *      free the original memory or otherwise access it.
  60  *
  61  *      Trailing whitespace is trimmed by inserting a NULL termination
  62  *      in the position at which the first trailing whitespce character
  63  *      lies. This routine can therefore modify the memory used by
  64  *      the input string.
  65  */
  66 char *
  67 conv_strproc_trim(char *str)
  68 {
  69         char    *tail;
  70
  71         /* Skip leading whitespace */
  72         while (conv_strproc_isspace(*str))
  73                 str++;
  74
  75         /* Back up over trailing whitespace */
  76         tail = str + strlen(str);
  77         while ((tail > str) && conv_strproc_isspace(*(tail - 1)))
  78                 tail--;
  79         *tail = '\0';
  80
  81         return (str);
  82 }
  83
  84 /*
  85  * Given a debug token of the form:
  86  *
  87  *      token=value
  88  *
  89  * extract and return a pointer to the value.
  90  *
  91  * entry:
  92  *      str - String to process
  93  *      token_len = Length of the token, not counting the '=' character,
  94  *              or any whitespace between the token and the '='.
  95  *      to_upper - True to convert the returned value to upper case.
  96  *      value - Address of pointer to receive the value string.
  97  *
  98  * exit:
  99  *      On success, *value is updated to point at the value string,
 100  *      and True (1) is returned. On failure, False (0) is returned.
 101  *
 102  * note:
 103  *      If CONV_SPEXV_F_UCASE is specified, this routine modifies
 104  *      the memory pointed at by str.
 105  */
 106 Boolean
 107 conv_strproc_extract_value(char *str, size_t token_len, int flags,
 108     const char **value)
 109 {
 110         int     trim = (flags & CONV_SPEXV_F_NOTRIM) == 0;
 111
 112         /* Skip the token */
 113         str += token_len;
 114
 115         /*
 116          * If TRIM, skip whitespace between token and '='
 117          */
 118         if (trim)
 119                 while (conv_strproc_isspace(*str))
 120                         str++;
 121
 122         /* If there's not a '=' here, this isn't the token we thought it was */
 123         if (*str != '=')
 124                 return (FALSE);
 125
 126         str++;                  /* skip the '=' */
 127
 128         /* if TRIM, skip whitespace following the '=' */
 129         if (trim)
 130                 while (conv_strproc_isspace(*str))
 131                         str++;
 132
 133         /* Null value and it's not OK? Make it an error. */
 134         if (((flags & CONV_SPEXV_F_NULLOK) == 0) && (*str == '\0'))
 135                 return (FALSE);
 136
 137         *value = str;
 138
 139         /* Convert to uppercase on request */
 140         if (flags & CONV_SPEXV_F_UCASE)
 141                 for (; *str; str++)
 142                         if ((*str >= 'a') && (*str <= 'z'))
 143                                 *str = *str - ('a' - 'A');
 144
 145         return (TRUE);
 146 }