1 /* $OpenBSD: vars.c,v 1.8 2001/11/21 20:41:56 millert Exp $ */ 2 /* $NetBSD: vars.c,v 1.4 1996/06/08 19:48:45 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1980, 1993 6 * The Regents of the University of California. All rights reserved. 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 #if 0 39 static const char sccsid[] = "@(#)vars.c 8.1 (Berkeley) 6/6/93"; 40 #else 41 static const char rcsid[] = "$OpenBSD: vars.c,v 1.8 2001/11/21 20:41:56 millert Exp $"; 42 #endif 43 #endif /* not lint */ 44 45 #include "rcv.h" 46 #include "extern.h" 47 48 /* 49 * Mail -- a mail program 50 * 51 * Variable handling stuff. 52 */ 53 54 /* 55 * Assign a value to a variable. 56 */ 57 void 58 assign(char *name, char *value) 59 { 60 struct var *vp; 61 int h; 62 63 h = hash(name); 64 vp = lookup(name); 65 if (vp == NULL) { 66 if ((vp = (struct var *)calloc(sizeof(*vp), 1)) == NULL) 67 errx(1, "Out of memory"); 68 vp->v_name = vcopy(name); 69 vp->v_link = variables[h]; 70 variables[h] = vp; 71 } 72 else 73 vfree(vp->v_value); 74 vp->v_value = vcopy(value); 75 } 76 77 /* 78 * Free up a variable string. We do not bother to allocate 79 * strings whose value is "" since they are expected to be frequent. 80 * Thus, we cannot free same! 81 */ 82 void 83 vfree(char *cp) 84 { 85 86 if (*cp) 87 (void)free(cp); 88 } 89 90 /* 91 * Copy a variable value into permanent (ie, not collected after each 92 * command) space. Do not bother to alloc space for "" 93 */ 94 char * 95 vcopy(char *str) 96 { 97 char *new; 98 99 if (*str == '\0') 100 return(""); 101 if ((new = strdup(str)) == NULL) 102 errx(1, "Out of memory"); 103 return(new); 104 } 105 106 /* 107 * Get the value of a variable and return it. 108 * Look in the environment if its not available locally. 109 */ 110 111 char * 112 value(char *name) 113 { 114 struct var *vp; 115 char *env; 116 117 if ((vp = lookup(name)) != NULL) 118 return(vp->v_value); 119 else if ((env = getenv(name))) 120 return(env); 121 /* not set, see if we can provide a default */ 122 else if (strcmp(name, "SHELL") == 0) 123 return(_PATH_CSHELL); 124 else if (strcmp(name, "LISTER") == 0) 125 return(_PATH_LS); 126 else if (strcmp(name, "PAGER") == 0) 127 return(_PATH_MORE); 128 else 129 return(NULL); 130 } 131 132 /* 133 * Locate a variable and return its variable 134 * node. 135 */ 136 struct var * 137 lookup(char *name) 138 { 139 struct var *vp; 140 141 for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link) 142 if (*vp->v_name == *name && equal(vp->v_name, name)) 143 return(vp); 144 return(NULL); 145 } 146 147 /* 148 * Locate a group name and return it. 149 */ 150 struct grouphead * 151 findgroup(char *name) 152 { 153 struct grouphead *gh; 154 155 for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link) 156 if (*gh->g_name == *name && equal(gh->g_name, name)) 157 return(gh); 158 return(NULL); 159 } 160 161 /* 162 * Print a group out on stdout 163 */ 164 void 165 printgroup(char *name) 166 { 167 struct grouphead *gh; 168 struct group *gp; 169 170 if ((gh = findgroup(name)) == NULL) { 171 printf("\"%s\": not a group\n", name); 172 return; 173 } 174 printf("%s\t", gh->g_name); 175 for (gp = gh->g_list; gp != NULL; gp = gp->ge_link) 176 printf(" %s", gp->ge_name); 177 putchar('\n'); 178 } 179 180 /* 181 * Hash the passed string and return an index into 182 * the variable or group hash table. 183 */ 184 int 185 hash(char *name) 186 { 187 int h = 0; 188 189 while (*name) { 190 h <<= 2; 191 h += *name++; 192 } 193 if (h < 0 && (h = -h) < 0) 194 h = 0; 195 return(h % HSHSIZE); 196 } 197