6.5 initial commit

9 files changed, 271 insertions, 0 deletions

diff --git a/6.5/Makefile b/6.5/Makefile
new file mode 100644
index 0000000..c99e8b9
--- /dev/null
+++ b/6.5/Makefile
@@ -0,0 +1,13 @@
+objects = main.o hash.o word.o getch.o
+CC = gcc
+CFLAGS = -Wvla -Wall -Wextra -Wstrict-prototypes -Wmissing-prototypes -fsanitize=address
+
+hash : $(objects)
+	$(CC) $(CFLAGS) -o hash $(objects)
+
+main.o : word.h hash.h
+word.o : getch.h
+
+.PHONY : clean
+clean:
+	rm hash $(objects)
diff --git a/6.5/getch.c b/6.5/getch.c
new file mode 100644
index 0000000..a473190
--- /dev/null
+++ b/6.5/getch.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <error.h>
+#include <errno.h>
+#include "getch.h"
+
+#define MAXBUFF 100
+
+int gtop;
+char buff[MAXBUFF];
+
+char getch(void)
+{
+	return (gtop > 0) ? buff[--gtop] : getchar();
+}
+
+void ungetch(char c)
+{
+	if (gtop < MAXBUFF)
+		buff[gtop++] = c;
+	else
+	 	error(EXIT_FAILURE, ENOBUFS, "getch");
+}
diff --git a/6.5/getch.h b/6.5/getch.h
new file mode 100644
index 0000000..b0e086b
--- /dev/null
+++ b/6.5/getch.h
@@ -0,0 +1,2 @@
+char getch(void);
+void ungetch(char c);
diff --git a/6.5/hash.c b/6.5/hash.c
new file mode 100644
index 0000000..1e29bd7
--- /dev/null
+++ b/6.5/hash.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "hash.h"
+
+void nlfree(struct nlist *p);
+uint32_t hash(char *s, uint32_t hashsize);
+struct nlist *lookup(struct nlist *hashtab[], uint32_t hashsize, char *s);
+void pnl(struct nlist *np);
+
+uint32_t hash(char *s, uint32_t hashsize)
+{
+	uint32_t hashval;
+
+	for (hashval = 0; *s != '\0'; ++s)
+		hashval = *s + 31*hashval;
+
+	return hashval % hashsize;
+}
+
+struct nlist *lookup(struct nlist *hashtab[], uint32_t hashsize, char *s)
+{
+	struct nlist *np;
+
+	for (np = hashtab[hash(s, hashsize)]; np != NULL; np = np->next)
+		if (!strcmp(s, np->name))
+			return np;
+
+	return NULL;
+}
+
+struct nlist *install(struct nlist *hashtab[], uint32_t hashsize,
+		      char *name, char *defn)
+{
+	struct nlist *np;
+	uint32_t hashval;
+
+	if ((np = lookup(hashtab, hashsize, name)) == NULL) {
+		np = (struct nlist *) malloc(sizeof(*np));
+		if (np == NULL || (np->name = strdup(name)) == NULL) {
+			nlfree(np);
+			return NULL;
+		}
+
+		hashval = hash(name, hashsize);
+		np->next = hashtab[hashval];
+		hashtab[hashval] = np;
+	} else {
+		free(np->defn);
+	}
+
+	if ((np->defn = strdup(defn)) == NULL) {
+		undef(hashtab, hashsize, name);
+		return NULL;
+	}
+
+	return np;
+}
+
+void undef(struct nlist *hashtab[], uint32_t hashsize, char *name)
+{
+	struct nlist *cur, *last;
+	uint32_t hashval = hash(name, hashsize);
+
+	for (cur = hashtab[hashval], last = NULL; cur !=NULL; last = cur,
+	     cur = cur->next) {
+		if (!strcmp(cur->name, name)) {
+			if (last == NULL)
+				hashtab[hashval] = cur->next;
+			else
+				last->next = cur->next;
+
+			cur->next = NULL;
+			nlfree(cur);
+			return;
+		}
+	}
+}
+
+void pnl(struct nlist *np)
+{
+	if (np != NULL) {
+		pnl(np->next);
+		printf("%10s %s\n", np->name, np->defn);
+	}
+}
+
+void phashtab(struct nlist *hashtab[], int lim)
+{
+	int i;
+
+	for (i = 0; i < lim; ++i)
+		pnl(hashtab[i]);
+}
+
+void nlfree(struct nlist *p)
+{
+	if (p != NULL ) {
+		nlfree(p->next);
+		if (p->defn != NULL)
+			free(p->defn);
+		if (p->name != NULL)
+			free(p->name);
+		free(p);
+	}
+}
+
+void hashfree(struct nlist *hashtab[], int lim)
+{
+	int i;
+
+	for (i = 0; i < lim; ++i)
+		nlfree(hashtab[i]);
+}
diff --git a/6.5/hash.h b/6.5/hash.h
new file mode 100644
index 0000000..b32e0d4
--- /dev/null
+++ b/6.5/hash.h
@@ -0,0 +1,18 @@
+#include <stdint.h>
+
+#ifndef HASH_H
+
+struct nlist {
+	struct nlist *next;
+	char *name;
+	char *defn;
+};
+
+#define HASH_H
+#endif
+
+struct nlist *install(struct nlist *hashtab[], uint32_t hashsize,
+		      char *name, char *defn);
+void undef(struct nlist *hashtab[], uint32_t hashsize, char *name);
+void phashtab(struct nlist *hastab[], int hashsize);
+void hashfree(struct nlist *hastab[], int hashsize);
diff --git a/6.5/main.c b/6.5/main.c
new file mode 100644
index 0000000..90bc87e
--- /dev/null
+++ b/6.5/main.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "word.h"
+#include "hash.h"
+
+#define MAXWORD		100
+#define HASHSIZE	100
+
+struct nlist *hashtab[HASHSIZE];
+
+int main(void)
+{
+	char word[MAXWORD];
+	char *name;
+
+	while (getword(word, MAXWORD) != EOF) {
+		if (!strcmp(word, "#define")) {
+			getword(word, MAXWORD);
+			name = strdup(word);
+			getword(word, MAXWORD);
+			install(hashtab, HASHSIZE, name, word);
+			free(name);
+		} else if (!strcmp(word, "#undef")) {
+			getword(word, MAXWORD);
+			undef(hashtab, HASHSIZE, word);
+		}
+	}
+
+	phashtab(hashtab, HASHSIZE);
+	hashfree(hashtab, HASHSIZE);
+
+	return 0;
+}
diff --git a/6.5/test.c b/6.5/test.c
new file mode 100644
index 0000000..d905c15
--- /dev/null
+++ b/6.5/test.c
@@ -0,0 +1,5 @@
+#define	sneed	feed
+#define	chuck	seek
+#define	based	soy
+#define	soy	based
+#undef	chuck
diff --git a/6.5/word.c b/6.5/word.c
new file mode 100644
index 0000000..045eaf7
--- /dev/null
+++ b/6.5/word.c
@@ -0,0 +1,58 @@
+// #include <stdio.h>
+// #include <stdlib.h>
+// #include <stdint.h>
+#include <ctype.h>
+// #include <string.h>
+// #include <error.h>
+// #include <errno.h>
+#include "getch.h"
+#include "word.h"
+
+// #define MAXBUFF 100
+//
+// uint32_t top;
+// char *wstack[MAXBUFF];
+
+char getword(char *word, int lim)
+{
+	char *w = word;
+
+	// if (top > 0)
+	// 	return *wstack[--top];
+
+	while (isblank(*w = getch()))
+		;
+	
+	if (isalpha(*w)) {
+		while ((isalnum(*++w = getch()) || *w == '_') && --lim > 0)
+			;
+		ungetch(*w--);
+	} else if (*w == '#') {
+		--lim;
+		do {
+			*++w = getch();
+		} while (isalpha(*w) && --lim > 0);
+		ungetch(*w--);
+	}
+
+	*++w = '\0';
+	return word[0];
+}
+//
+// void ungetword(char *word)
+// {
+// 	if (top < MAXBUFF) {
+// 		if ((wstack[top++] = strdup(word)) == NULL)
+// 			error(EXIT_FAILURE, ENOBUFS, "ungetword");
+// 	} else {
+// 		error(EXIT_FAILURE, ENOBUFS, "ungetword");
+// 	}
+// }
+//
+// void wordfree(void)
+// {
+// 	uint32_t i;
+//
+// 	for (i = 0; i < top; ++i)
+// 		free(wstack[i]);
+// }
diff --git a/6.5/word.h b/6.5/word.h
new file mode 100644
index 0000000..fcd8240
--- /dev/null
+++ b/6.5/word.h
@@ -0,0 +1,3 @@
+char getword(char *word, int lim);
+// void ungetword(char *word);
+// void wordfree(void);