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Diffstat (limited to 'bin/sh/alias.c')
-rw-r--r-- | bin/sh/alias.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/bin/sh/alias.c b/bin/sh/alias.c new file mode 100644 index 0000000..3cf38a9 --- /dev/null +++ b/bin/sh/alias.c @@ -0,0 +1,251 @@ +/*- + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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. + */ + +#ifndef lint +static char sccsid[] = "@(#)alias.c 8.1 (Berkeley) 5/31/93"; +#endif /* not lint */ + +#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?) */ + +#define ATABSIZE 39 + +struct alias *atab[ATABSIZE]; + +STATIC struct alias **hashalias __P((char *)); + +STATIC +setalias(name, val) + char *name, *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); + /* + * 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); + bcopy(val, ap->val, len); + ap->val[len] = ' '; /* fluff */ + ap->val[len+1] = '\0'; + } +#endif + ap->next = *app; + *app = ap; + INTON; +} + +STATIC int +unalias(name) + 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(); + +SHELLPROC { + rmaliases(); +} +#endif + +void +rmaliases() { + 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(name, check) + char *name; + { + 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); +} + +/* + * TODO - sort output + */ +aliascmd(argc, argv) + 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=%s\n", ap->name, ap->val); + } + return (0); + } + while (n = *++argv) { + 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=%s\n", n, ap->val); + else { + *v++ = '\0'; + setalias(n, v); + } + } + + return (ret); +} + +unaliascmd(argc, argv) + 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(p) + register char *p; + { + unsigned int hashval; + + hashval = *p << 4; + while (*p) + hashval+= *p++; + return &atab[hashval % ATABSIZE]; +} |