sh: Constify various strings.

Most of this is adding const keywords, but setvar() in var.c had to be
changed somewhat more.

bin/sh/alias.c

@@ -52,13 +52,13 @@ __FBSDID("$FreeBSD$");
 STATIC struct alias *atab[ATABSIZE];
 STATIC int aliases;
 
-STATIC void setalias(char *, char *);
+STATIC void setalias(const char *, const char *);
 STATIC int unalias(const char *);
 STATIC struct alias **hashalias(const char *);
 
 STATIC
 void
-setalias(char *name, char *val)
+setalias(const char *name, const char *val)
 {
 	struct alias *ap, **app;
 
@@ -176,7 +176,7 @@ rmaliases(void)
 }
 
 struct alias *
-lookupalias(char *name, int check)
+lookupalias(const char *name, int check)
 {
 	struct alias *ap = *hashalias(name);
 

bin/sh/alias.h

@@ -42,7 +42,7 @@ struct alias {
 	int flag;
 };
 
-struct alias *lookupalias(char *, int);
+struct alias *lookupalias(const char *, int);
 int aliascmd(int, char **);
 int unaliascmd(int, char **);
 void rmaliases(void);

bin/sh/arith.h

@@ -34,8 +34,8 @@
 
 #define DIGITS(var) (3 + (2 + CHAR_BIT * sizeof((var))) / 3)
 
-extern char *arith_buf, *arith_startbuf;
+extern const char *arith_buf, *arith_startbuf;
 
-arith_t arith(char *);
+arith_t arith(const char *);
 void arith_lex_reset(void);
 int expcmd(int, char **);

bin/sh/arith.y

@@ -265,7 +265,7 @@ expr:
 #define YYPARSE_PARAM_TYPE arith_t *
 #define YYPARSE_PARAM result
 
-char *arith_buf, *arith_startbuf;
+const char *arith_buf, *arith_startbuf;
 
 int yylex(void);
 int yyparse(YYPARSE_PARAM_TYPE);
@@ -284,7 +284,7 @@ arith_assign(char *name, arith_t value)
 }
 
 arith_t
-arith(char *s)
+arith(const char *s)
 {
 	arith_t result;
 
@@ -299,7 +299,7 @@ arith(char *s)
 }
 
 static void
-yyerror(char *s)
+yyerror(const char *s)
 {
 
 	yyerrok;
@@ -354,7 +354,7 @@ main(int argc, char *argv[])
 	printf("%d\n", exp(argv[1]));
 }
 
-error(char *s)
+error(const char *s)
 {
 	fprintf(stderr, "exp: %s\n", s);
 	exit(1);

bin/sh/cd.c

@@ -80,7 +80,7 @@ int
 cdcmd(int argc, char **argv)
 {
 	char *dest;
-	char *path;
+	const char *path;
 	char *p;
 	struct stat statb;
 	int ch, phys, print = 0;

bin/sh/exec.c

@@ -98,7 +98,7 @@ int exerrno = 0;			/* Last exec error */
 
 STATIC void tryexec(char *, char **, char **);
 STATIC void printentry(struct tblentry *, int);
-STATIC struct tblentry *cmdlookup(char *, int);
+STATIC struct tblentry *cmdlookup(const char *, int);
 STATIC void delete_cmd_entry(void);
 
 
@@ -109,7 +109,7 @@ STATIC void delete_cmd_entry(void);
  */
 
 void
-shellexec(char **argv, char **envp, char *path, int index)
+shellexec(char **argv, char **envp, const char *path, int index)
 {
 	char *cmdname;
 	int e;
@@ -175,13 +175,13 @@ tryexec(char *cmd, char **argv, char **envp)
  * NULL.
  */
 
-char *pathopt;
+const char *pathopt;
 
 char *
-padvance(char **path, char *name)
+padvance(const char **path, const char *name)
 {
-	char *p, *q;
-	char *start;
+	const char *p, *start;
+	char *q;
 	int len;
 
 	if (*path == NULL)
@@ -269,7 +269,7 @@ STATIC void
 printentry(struct tblentry *cmdp, int verbose)
 {
 	int index;
-	char *path;
+	const char *path;
 	char *name;
 
 	if (cmdp->cmdtype == CMDNORMAL) {
@@ -310,7 +310,8 @@ printentry(struct tblentry *cmdp, int verbose)
  */
 
 void
-find_command(char *name, struct cmdentry *entry, int printerr, char *path)
+find_command(const char *name, struct cmdentry *entry, int printerr,
+    const char *path)
 {
 	struct tblentry *cmdp;
 	int index;
@@ -446,7 +447,7 @@ find_command(char *name, struct cmdentry *entry, int printerr, char *path)
  */
 
 int
-find_builtin(char *name, int *special)
+find_builtin(const char *name, int *special)
 {
 	const struct builtincmd *bp;
 
@@ -608,10 +609,10 @@ STATIC struct tblentry **lastcmdentry;
 
 
 STATIC struct tblentry *
-cmdlookup(char *name, int add)
+cmdlookup(const char *name, int add)
 {
 	int hashval;
-	char *p;
+	const char *p;
 	struct tblentry *cmdp;
 	struct tblentry **pp;
 
@@ -664,7 +665,7 @@ delete_cmd_entry(void)
  */
 
 void
-addcmdentry(char *name, struct cmdentry *entry)
+addcmdentry(const char *name, struct cmdentry *entry)
 {
 	struct tblentry *cmdp;
 
@@ -684,7 +685,7 @@ addcmdentry(char *name, struct cmdentry *entry)
  */
 
 void
-defun(char *name, union node *func)
+defun(const char *name, union node *func)
 {
 	struct cmdentry entry;
 
@@ -701,7 +702,7 @@ defun(char *name, union node *func)
  */
 
 int
-unsetfunc(char *name)
+unsetfunc(const char *name)
 {
 	struct tblentry *cmdp;
 
@@ -767,7 +768,8 @@ typecmd_impl(int argc, char **argv, int cmd)
 		switch (entry.cmdtype) {
 		case CMDNORMAL: {
 			if (strchr(argv[i], '/') == NULL) {
-				char *path = pathval(), *name;
+				const char *path = pathval();
+				char *name;
 				int j = entry.u.index;
 				do {
 					name = padvance(&path, argv[i]);

bin/sh/exec.h

@@ -57,20 +57,20 @@ struct cmdentry {
 };
 
 
-extern char *pathopt;		/* set by padvance */
+extern const char *pathopt;	/* set by padvance */
 extern int exerrno;		/* last exec error */
 
-void shellexec(char **, char **, char *, int);
-char *padvance(char **, char *);
+void shellexec(char **, char **, const char *, int);
+char *padvance(const char **, const char *);
 int hashcmd(int, char **);
-void find_command(char *, struct cmdentry *, int, char *);
-int find_builtin(char *, int *);
+void find_command(const char *, struct cmdentry *, int, const char *);
+int find_builtin(const char *, int *);
 void hashcd(void);
 void changepath(const char *);
 void deletefuncs(void);
-void addcmdentry(char *, struct cmdentry *);
-void defun(char *, union node *);
-int unsetfunc(char *);
+void addcmdentry(const char *, struct cmdentry *);
+void defun(const char *, union node *);
+int unsetfunc(const char *);
 int typecmd_impl(int, char **, int);
 int typecmd(int, char **);
 void clearcmdentry(int);

bin/sh/expand.c

@@ -107,7 +107,7 @@ STATIC void expmeta(char *, char *);
 STATIC void addfname(char *);
 STATIC struct strlist *expsort(struct strlist *);
 STATIC struct strlist *msort(struct strlist *, int);
-STATIC int pmatch(char *, char *, int);
+STATIC int pmatch(const char *, const char *, int);
 STATIC char *cvtnum(int, char *);
 STATIC int collate_range_cmp(int, int);
 
@@ -1338,7 +1338,7 @@ msort(struct strlist *list, int len)
  */
 
 int
-patmatch(char *pattern, char *string, int squoted)
+patmatch(const char *pattern, const char *string, int squoted)
 {
 #ifdef notdef
 	if (pattern[0] == '!' && pattern[1] == '!')
@@ -1350,9 +1350,9 @@ patmatch(char *pattern, char *string, int squoted)
 
 
 STATIC int
-pmatch(char *pattern, char *string, int squoted)
+pmatch(const char *pattern, const char *string, int squoted)
 {
-	char *p, *q;
+	const char *p, *q;
 	char c;
 
 	p = pattern;
@@ -1400,7 +1400,7 @@ pmatch(char *pattern, char *string, int squoted)
 			} while (*q++ != '\0');
 			return 0;
 		case '[': {
-			char *endp;
+			const char *endp;
 			int invert, found;
 			char chr;
 
@@ -1504,7 +1504,7 @@ rmescapes(char *str)
  */
 
 int
-casematch(union node *pattern, char *val)
+casematch(union node *pattern, const char *val)
 {
 	struct stackmark smark;
 	int result;

bin/sh/expand.h

@@ -58,7 +58,7 @@ union node;
 void expandhere(union node *, int);
 void expandarg(union node *, struct arglist *, int);
 void expari(int);
-int patmatch(char *, char *, int);
+int patmatch(const char *, const char *, int);
 void rmescapes(char *);
-int casematch(union node *, char *);
+int casematch(union node *, const char *);
 int wordexpcmd(int, char **);

bin/sh/histedit.c

@@ -406,7 +406,7 @@ fc_replace(const char *s, char *p, char *r)
 }
 
 int
-not_fcnumber(char *s)
+not_fcnumber(const char *s)
 {
 	if (s == NULL)
 		return (0);
@@ -416,10 +416,10 @@ not_fcnumber(char *s)
 }
 
 int
-str_to_event(char *str, int last)
+str_to_event(const char *str, int last)
 {
 	HistEvent he;
-	char *s = str;
+	const char *s = str;
 	int relative = 0;
 	int i, retval;
 

bin/sh/input.c

@@ -401,7 +401,7 @@ popstring(void)
  */
 
 void
-setinputfile(char *fname, int push)
+setinputfile(const char *fname, int push)
 {
 	int fd;
 	int fd2;

bin/sh/input.h

@@ -54,7 +54,7 @@ int preadateof(void);
 void pungetc(void);
 void pushstring(char *, int, void *);
 void popstring(void);
-void setinputfile(char *, int);
+void setinputfile(const char *, int);
 void setinputfd(int, int);
 void setinputstring(char *, int);
 void popfile(void);

bin/sh/mail.c

@@ -72,7 +72,7 @@ void
 chkmail(int silent)
 {
 	int i;
-	char *mpath;
+	const char *mpath;
 	char *p;
 	char *q;
 	struct stackmark smark;

bin/sh/main.c

@@ -269,7 +269,7 @@ read_profile(char *name)
  */
 
 void
-readcmdfile(char *name)
+readcmdfile(const char *name)
 {
 	int fd;
 
@@ -296,7 +296,7 @@ find_dot_file(char *basename)
 {
 	static char localname[FILENAME_MAX+1];
 	char *fullname;
-	char *path = pathval();
+	const char *path = pathval();
 	struct stat statb;
 
 	/* don't try this for absolute or relative paths */

bin/sh/main.h

@@ -36,7 +36,7 @@
 extern int rootpid;	/* pid of main shell */
 extern int rootshell;	/* true if we aren't a child of the main shell */
 
-void readcmdfile(char *);
+void readcmdfile(const char *);
 void cmdloop(int);
 int dotcmd(int, char **);
 int exitcmd(int, char **);

bin/sh/memalloc.c

@@ -95,7 +95,7 @@ ckfree(pointer p)
  */
 
 char *
-savestr(char *s)
+savestr(const char *s)
 {
 	char *p;
 

bin/sh/memalloc.h

@@ -51,7 +51,7 @@ extern int herefd;
 pointer ckmalloc(size_t);
 pointer ckrealloc(pointer, int);
 void ckfree(pointer);
-char *savestr(char *);
+char *savestr(const char *);
 pointer stalloc(int);
 void stunalloc(pointer);
 void setstackmark(struct stackmark *);

bin/sh/myhistedit.h

@@ -39,7 +39,7 @@ extern int displayhist;
 void histedit(void);
 void sethistsize(const char *);
 int histcmd(int, char **);
-int not_fcnumber(char *);
-int str_to_event(char *, int);
+int not_fcnumber(const char *);
+int str_to_event(const char *, int);
 int bindcmd(int, char **);
 

bin/sh/options.c

@@ -554,9 +554,10 @@ getopts(char *optstr, char *optvar, char **optfirst, char ***optnext,
  */
 
 int
-nextopt(char *optstring)
+nextopt(const char *optstring)
 {
-	char *p, *q;
+	char *p;
+	const char *q;
 	char c;
 
 	if ((p = optptr) == NULL || *p == '\0') {

bin/sh/options.h

@@ -111,5 +111,5 @@ void freeparam(struct shparam *);
 int shiftcmd(int, char **);
 int setcmd(int, char **);
 int getoptscmd(int, char **);
-int nextopt(char *);
+int nextopt(const char *);
 void getoptsreset(const char *);

bin/sh/output.c

@@ -314,7 +314,7 @@ doformat(struct output *dest, const char *f, va_list ap)
  */
 
 int
-xwrite(int fd, char *buf, int nbytes)
+xwrite(int fd, const char *buf, int nbytes)
 {
 	int ntry;
 	int i;

bin/sh/output.h

@@ -68,7 +68,7 @@ void out1fmt(const char *, ...) __printflike(1, 2);
 void out2fmt_flush(const char *, ...) __printflike(1, 2);
 void fmtstr(char *, int, const char *, ...) __printflike(3, 4);
 void doformat(struct output *, const char *, va_list) __printflike(2, 0);
-int xwrite(int, char *, int);
+int xwrite(int, const char *, int);
 
 #define outc(c, file)	(--(file)->nleft < 0? (emptyoutbuf(file), *(file)->nextc++ = (c)) : (*(file)->nextc++ = (c)))
 #define out1c(c)	outc(c, out1);

bin/sh/parser.c

@@ -1510,9 +1510,9 @@ noexpand(char *text)
  */
 
 int
-goodname(char *name)
+goodname(const char *name)
 {
-	char *p;
+	const char *p;
 
 	p = name;
 	if (! is_name(*p))

bin/sh/parser.h

@@ -77,5 +77,5 @@ extern int whichprompt;		/* 1 == PS1, 2 == PS2 */
 
 union node *parsecmd(int);
 void fixredir(union node *, const char *, int);
-int goodname(char *);
+int goodname(const char *);
 char *getprompt(void *);

bin/sh/show.c

@@ -307,7 +307,7 @@ sh_trace(const char *fmt, ...)
 
 
 void
-trputs(char *s)
+trputs(const char *s)
 {
 	if (tracefile == NULL)
 		return;

bin/sh/show.h

@@ -35,6 +35,6 @@ void showtree(union node *);
 void sh_trace(const char *, ...) __printflike(1, 2);
 void trargs(char **);
 void trputc(int);
-void trputs(char *);
+void trputs(const char *);
 void opentrace(void);
 #endif

bin/sh/var.c

@@ -122,9 +122,9 @@ STATIC const struct varinit varinit[] = {
 
 STATIC struct var *vartab[VTABSIZE];
 
-STATIC struct var **hashvar(char *);
-STATIC int varequal(char *, char *);
-STATIC int localevar(char *);
+STATIC struct var **hashvar(const char *);
+STATIC int varequal(const char *, const char *);
+STATIC int localevar(const char *);
 
 /*
  * Initialize the variable symbol tables and import the environment.
@@ -190,7 +190,7 @@ initvar(void)
  */
 
 int
-setvarsafe(char *name, char *val, int flags)
+setvarsafe(const char *name, const char *val, int flags)
 {
 	struct jmploc jmploc;
 	struct jmploc *const savehandler = handler;
@@ -215,9 +215,9 @@ setvarsafe(char *name, char *val, int flags)
  */
 
 void
-setvar(char *name, char *val, int flags)
+setvar(const char *name, const char *val, int flags)
 {
-	char *p, *q;
+	const char *p;
 	int len;
 	int namelen;
 	char *nameeq;
@@ -245,19 +245,18 @@ setvar(char *name, char *val, int flags)
 	} else {
 		len += strlen(val);
 	}
-	p = nameeq = ckmalloc(len);
-	q = name;
-	while (--namelen >= 0)
-		*p++ = *q++;
-	*p++ = '=';
-	*p = '\0';
+	nameeq = ckmalloc(len);
+	memcpy(nameeq, name, namelen);
+	nameeq[namelen] = '=';
 	if (val)
-		scopy(val, p);
+		scopy(val, nameeq + namelen + 1);
+	else
+		nameeq[namelen + 1] = '\0';
 	setvareq(nameeq, flags);
 }
 
 STATIC int
-localevar(char *s)
+localevar(const char *s)
 {
 	static char *lnames[7] = {
 		"ALL", "COLLATE", "CTYPE", "MONETARY",
@@ -283,7 +282,7 @@ localevar(char *s)
  * pointer into environ where the string should not be manipulated.
  */
 static void
-change_env(char *s, int set)
+change_env(const char *s, int set)
 {
 	char *eqp;
 	char *ss;
@@ -389,7 +388,7 @@ listsetvar(struct strlist *list)
  */
 
 char *
-lookupvar(char *name)
+lookupvar(const char *name)
 {
 	struct var *v;
 
@@ -412,7 +411,7 @@ lookupvar(char *name)
  */
 
 char *
-bltinlookup(char *name, int doall)
+bltinlookup(const char *name, int doall)
 {
 	struct strlist *sp;
 	struct var *v;
@@ -796,7 +795,7 @@ unsetcmd(int argc __unused, char **argv __unused)
  */
 
 int
-unsetvar(char *s)
+unsetvar(const char *s)
 {
 	struct var **vpp;
 	struct var *vp;
@@ -836,7 +835,7 @@ unsetvar(char *s)
  */
 
 STATIC struct var **
-hashvar(char *p)
+hashvar(const char *p)
 {
 	unsigned int hashval;
 
@@ -855,7 +854,7 @@ hashvar(char *p)
  */
 
 STATIC int
-varequal(char *p, char *q)
+varequal(const char *p, const char *q)
 {
 	while (*p == *q++) {
 		if (*p++ == '=')

bin/sh/var.h

@@ -101,12 +101,12 @@ extern struct var vhistsize;
 #define mpathset()	((vmpath.flags & VUNSET) == 0)
 
 void initvar(void);
-void setvar(char *, char *, int);
+void setvar(const char *, const char *, int);
 void setvareq(char *, int);
 struct strlist;
 void listsetvar(struct strlist *);
-char *lookupvar(char *);
-char *bltinlookup(char *, int);
+char *lookupvar(const char *);
+char *bltinlookup(const char *, int);
 char **environment(void);
 void shprocvar(void);
 int showvarscmd(int, char **);
@@ -116,5 +116,5 @@ void mklocal(char *);
 void poplocalvars(void);
 int setvarcmd(int, char **);
 int unsetcmd(int, char **);
-int unsetvar(char *);
-int setvarsafe(char *, char *, int);
+int unsetvar(const char *);
+int setvarsafe(const char *, const char *, int);