sh/alias.c

   1 /*-
   2  * Copyright (c) 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Kenneth Almquist.
   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  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)alias.c     8.3 (Berkeley) 5/4/95";
  36 #endif
  37 #endif /* not lint */
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD: head/bin/sh/alias.c 295868 2016-02-21 20:58:24Z jilles $");
  40
  41 #include <stdlib.h>
  42 #include "shell.h"
  43 #include "output.h"
  44 #include "error.h"
  45 #include "memalloc.h"
  46 #include "mystring.h"
  47 #include "alias.h"
  48 #include "options.h"    /* XXX for argptr (should remove?) */
  49 #include "builtins.h"
  50
  51 #define ATABSIZE 39
  52
  53 static struct alias *atab[ATABSIZE];
  54 static int aliases;
  55
  56 static void setalias(const char *, const char *);
  57 static int unalias(const char *);
  58 static struct alias **hashalias(const char *);
  59
  60 static
  61 void
  62 setalias(const char *name, const char *val)
  63 {
  64         struct alias *ap, **app;
  65
  66         app = hashalias(name);
  67         for (ap = *app; ap; ap = ap->next) {
  68                 if (equal(name, ap->name)) {
  69                         INTOFF;
  70                         ckfree(ap->val);
  71                         ap->val = savestr(val);
  72                         INTON;
  73                         return;
  74                 }
  75         }
  76         /* not found */
  77         INTOFF;
  78         ap = ckmalloc(sizeof (struct alias));
  79         ap->name = savestr(name);
  80         ap->val = savestr(val);
  81         ap->flag = 0;
  82         ap->next = *app;
  83         *app = ap;
  84         aliases++;
  85         INTON;
  86 }
  87
  88 static int
  89 unalias(const char *name)
  90 {
  91         struct alias *ap, **app;
  92
  93         app = hashalias(name);
  94
  95         for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
  96                 if (equal(name, ap->name)) {
  97                         /*
  98                          * if the alias is currently in use (i.e. its
  99                          * buffer is being used by the input routine) we
 100                          * just null out the name instead of freeing it.
 101                          * We could clear it out later, but this situation
 102                          * is so rare that it hardly seems worth it.
 103                          */
 104                         if (ap->flag & ALIASINUSE)
 105                                 *ap->name = '\0';
 106                         else {
 107                                 INTOFF;
 108                                 *app = ap->next;
 109                                 ckfree(ap->name);
 110                                 ckfree(ap->val);
 111                                 ckfree(ap);
 112                                 INTON;
 113                         }
 114                         aliases--;
 115                         return (0);
 116                 }
 117         }
 118
 119         return (1);
 120 }
 121
 122 static void
 123 rmaliases(void)
 124 {
 125         struct alias *ap, *tmp;
 126         int i;
 127
 128         INTOFF;
 129         for (i = 0; i < ATABSIZE; i++) {
 130                 ap = atab[i];
 131                 atab[i] = NULL;
 132                 while (ap) {
 133                         ckfree(ap->name);
 134                         ckfree(ap->val);
 135                         tmp = ap;
 136                         ap = ap->next;
 137                         ckfree(tmp);
 138                 }
 139         }
 140         aliases = 0;
 141         INTON;
 142 }
 143
 144 struct alias *
 145 lookupalias(const char *name, int check)
 146 {
 147         struct alias *ap;
 148
 149         if (aliases == 0)
 150                 return (NULL);
 151         for (ap = *hashalias(name); ap; ap = ap->next) {
 152                 if (equal(name, ap->name)) {
 153                         if (check && (ap->flag & ALIASINUSE))
 154                                 return (NULL);
 155                         return (ap);
 156                 }
 157         }
 158
 159         return (NULL);
 160 }
 161
 162 static int
 163 comparealiases(const void *p1, const void *p2)
 164 {
 165         const struct alias *const *a1 = p1;
 166         const struct alias *const *a2 = p2;
 167
 168         return strcmp((*a1)->name, (*a2)->name);
 169 }
 170
 171 static void
 172 printalias(const struct alias *a)
 173 {
 174         out1fmt("%s=", a->name);
 175         out1qstr(a->val);
 176         out1c('\n');
 177 }
 178
 179 static void
 180 printaliases(void)
 181 {
 182         int i, j;
 183         struct alias **sorted, *ap;
 184
 185         INTOFF;
 186         sorted = ckmalloc(aliases * sizeof(*sorted));
 187         j = 0;
 188         for (i = 0; i < ATABSIZE; i++)
 189                 for (ap = atab[i]; ap; ap = ap->next)
 190                         if (*ap->name != '\0')
 191                                 sorted[j++] = ap;
 192         qsort(sorted, aliases, sizeof(*sorted), comparealiases);
 193         for (i = 0; i < aliases; i++) {
 194                 printalias(sorted[i]);
 195                 if (int_pending())
 196                         break;
 197         }
 198         ckfree(sorted);
 199         INTON;
 200 }
 201
 202 int
 203 aliascmd(int argc __unused, char **argv __unused)
 204 {
 205         char *n, *v;
 206         int ret = 0;
 207         struct alias *ap;
 208
 209         nextopt("");
 210
 211         if (*argptr == NULL) {
 212                 printaliases();
 213                 return (0);
 214         }
 215         while ((n = *argptr++) != NULL) {
 216                 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
 217                         if ((ap = lookupalias(n, 0)) == NULL) {
 218                                 warning("%s: not found", n);
 219                                 ret = 1;
 220                         } else
 221                                 printalias(ap);
 222                 else {
 223                         *v++ = '\0';
 224                         setalias(n, v);
 225                 }
 226         }
 227
 228         return (ret);
 229 }
 230
 231 int
 232 unaliascmd(int argc __unused, char **argv __unused)
 233 {
 234         int i;
 235
 236         while ((i = nextopt("a")) != '\0') {
 237                 if (i == 'a') {
 238                         rmaliases();
 239                         return (0);
 240                 }
 241         }
 242         for (i = 0; *argptr; argptr++)
 243                 i |= unalias(*argptr);
 244
 245         return (i);
 246 }
 247
 248 static struct alias **
 249 hashalias(const char *p)
 250 {
 251         unsigned int hashval;
 252
 253         hashval = (unsigned char)*p << 4;
 254         while (*p)
 255                 hashval+= *p++;
 256         return &atab[hashval % ATABSIZE];
 257 }