/* $NetBSD: alias.c,v 1.16 2017/07/24 12:34:45 kre Exp $ */ /*- * Copyright (c) 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #ifndef lint #if 0 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; #else __RCSID("$NetBSD: alias.c,v 1.16 2017/07/24 12:34:45 kre Exp $"); #endif #endif /* not lint */ #include #include "shell.h" #include "input.h" #include "output.h" #include "error.h" #include "memalloc.h" #include "mystring.h" #include "alias.h" #include "options.h" /* XXX for argptr (should remove?) */ #include "builtins.h" #include "var.h" #define ATABSIZE 39 struct alias *atab[ATABSIZE]; STATIC void setalias(char *, char *); STATIC int unalias(char *); STATIC struct alias **hashalias(const char *); STATIC void setalias(char *name, char *val) { struct alias *ap, **app; app = hashalias(name); for (ap = *app; ap; ap = ap->next) { if (equal(name, ap->name)) { INTOFF; ckfree(ap->val); ap->val = savestr(val); INTON; return; } } /* not found */ INTOFF; ap = ckmalloc(sizeof (struct alias)); ap->name = savestr(name); ap->flag = 0; /* * XXX - HACK: in order that the parser will not finish reading the * alias value off the input before processing the next alias, we * dummy up an extra space at the end of the alias. This is a crock * and should be re-thought. The idea (if you feel inclined to help) * is to avoid alias recursions. The mechanism used is: when * expanding an alias, the value of the alias is pushed back on the * input as a string and a pointer to the alias is stored with the * string. The alias is marked as being in use. When the input * routine finishes reading the string, it markes the alias not * in use. The problem is synchronization with the parser. Since * it reads ahead, the alias is marked not in use before the * resulting token(s) is next checked for further alias sub. The * H A C K is that we add a little fluff after the alias value * so that the string will not be exhausted. This is a good * idea ------- ***NOT*** */ #ifdef notyet ap->val = savestr(val); #else /* hack */ { int len = strlen(val); ap->val = ckmalloc(len + 2); memcpy(ap->val, val, len); ap->val[len] = ' '; /* fluff */ ap->val[len+1] = '\0'; } #endif ap->next = *app; *app = ap; INTON; } STATIC int unalias(char *name) { struct alias *ap, **app; app = hashalias(name); for (ap = *app; ap; app = &(ap->next), ap = ap->next) { if (equal(name, ap->name)) { /* * if the alias is currently in use (i.e. its * buffer is being used by the input routine) we * just null out the name instead of freeing it. * We could clear it out later, but this situation * is so rare that it hardly seems worth it. */ if (ap->flag & ALIASINUSE) *ap->name = '\0'; else { INTOFF; *app = ap->next; ckfree(ap->name); ckfree(ap->val); ckfree(ap); INTON; } return (0); } } return (1); } #ifdef mkinit MKINIT void rmaliases(void); SHELLPROC { rmaliases(); } #endif void rmaliases(void) { struct alias *ap, *tmp; int i; INTOFF; for (i = 0; i < ATABSIZE; i++) { ap = atab[i]; atab[i] = NULL; while (ap) { ckfree(ap->name); ckfree(ap->val); tmp = ap; ap = ap->next; ckfree(tmp); } } INTON; } struct alias * lookupalias(const char *name, int check) { struct alias *ap = *hashalias(name); for (; ap; ap = ap->next) { if (equal(name, ap->name)) { if (check && (ap->flag & ALIASINUSE)) return (NULL); return (ap); } } return (NULL); } const char * alias_text(void *dummy __unused, const char *name) { struct alias *ap; ap = lookupalias(name, 0); if (ap == NULL) return NULL; return ap->val; } /* * TODO - sort output */ int aliascmd(int argc, char **argv) { char *n, *v; int ret = 0; struct alias *ap; if (argc == 1) { int i; for (i = 0; i < ATABSIZE; i++) for (ap = atab[i]; ap; ap = ap->next) { if (*ap->name != '\0') { out1fmt("alias %s=", ap->name); print_quoted(ap->val); out1c('\n'); } } return (0); } while ((n = *++argv) != NULL) { if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */ if ((ap = lookupalias(n, 0)) == NULL) { outfmt(out2, "alias: %s not found\n", n); ret = 1; } else { out1fmt("alias %s=", n); print_quoted(ap->val); out1c('\n'); } } else { *v++ = '\0'; setalias(n, v); } } return (ret); } int unaliascmd(int argc, char **argv) { int i; while ((i = nextopt("a")) != '\0') { if (i == 'a') { rmaliases(); return (0); } } for (i = 0; *argptr; argptr++) i = unalias(*argptr); return (i); } STATIC struct alias ** hashalias(const char *p) { unsigned int hashval; hashval = *(const unsigned char *)p << 4; while (*p) hashval += *p++; return &atab[hashval % ATABSIZE]; }