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];
+}