Support the SysV-style -exec utility args.. {} + function, required by

SUSv3. This is similar to find foo -print0 | xargs -0 utility args.

usr.bin/find/find.1

@@ -294,6 +294,15 @@ and
 .Ar arguments
 are not subject to the further expansion of shell patterns
 and constructs.
+.It Ic -exec Ar utility Oo Ar argument ... Oc {} +
+Same as
+.Ic -exec ,
+except that
+.Dq Li {}
+is replaced with as many pathnames as possible for each invocation of
+.Ar utility .
+This behaviour is similar to that of
+.Xr xargs 1 .
 .It Ic -execdir Ar utility Op Ar argument ... ;
 The
 .Ic -execdir

usr.bin/find/find.c

@@ -235,6 +235,10 @@ find_execute(plan, paths)
 			continue;
 		}
 	}
+	/* Finish any pending -exec ... {} + functions. */
+	for (p = plan; p != NULL; p = p->next)
+		if (p->execute == f_exec && p->flags & F_EXECPLUS)
+			(p->execute)(p, NULL);
 	if (errno)
 		err(1, "fts_read");
 	return (rval);

usr.bin/find/find.h

@@ -70,6 +70,7 @@ typedef	struct _plandata *creat_f(struct _option *, char ***);
 #define	F_MTUNKNOWN	0x00002000
 #define	F_IGNCASE	0x00010000	/* iname ipath iregex */
 #define	F_EXACTTIME	F_IGNCASE	/* -[acm]time units syntax */
+#define F_EXECPLUS	0x00020000	/* -exec ... {} + */
 
 /* node definition */
 typedef struct _plandata {
@@ -94,6 +95,12 @@ typedef struct _plandata {
 			char **_e_argv;		/* argv array */
 			char **_e_orig;		/* original strings */
 			int *_e_len;		/* allocated length */
+			int _e_pbnum;		/* base num. of args. used */
+			int _e_ppos;		/* number of arguments used */
+			int _e_pnummax;		/* max. number of arguments */
+			int _e_psize;		/* number of bytes of args. */
+			int _e_pbsize;		/* base num. of bytes of args */
+			int _e_psizemax;	/* max num. of bytes of args */
 		} ex;
 		char *_a_data[2];		/* array of char pointers */
 		char *_c_data;			/* char pointer */
@@ -117,6 +124,12 @@ typedef struct _plandata {
 #define	e_argv	p_un.ex._e_argv
 #define	e_orig	p_un.ex._e_orig
 #define	e_len	p_un.ex._e_len
+#define e_pbnum	p_un.ex._e_pbnum
+#define e_ppos	p_un.ex._e_ppos
+#define e_pnummax p_un.ex._e_pnummax
+#define e_psize p_un.ex._e_psize
+#define e_pbsize p_un.ex._e_pbsize
+#define e_psizemax p_un.ex._e_psizemax
 
 typedef struct _option {
 	const char *name;		/* option name */

usr.bin/find/function.c

@@ -55,6 +55,7 @@ __FBSDID("$FreeBSD$");
 #include <fnmatch.h>
 #include <fts.h>
 #include <grp.h>
+#include <limits.h>
 #include <pwd.h>
 #include <regex.h>
 #include <stdio.h>
@@ -528,6 +529,13 @@ f_exec(plan, entry)
 	int status;
 	char *file;
 
+	if (entry == NULL && plan->flags & F_EXECPLUS) {
+		if (plan->e_ppos == plan->e_pbnum)
+			return (1);
+		plan->e_argv[plan->e_ppos] = NULL;
+		goto doexec;
+	}
+
 	/* XXX - if file/dir ends in '/' this will not work -- can it? */
 	if ((plan->flags & F_EXECDIR) && \
 	    (file = strrchr(entry->fts_path, '/')))
@@ -535,12 +543,24 @@ f_exec(plan, entry)
 	else
 		file = entry->fts_path;
 
-	for (cnt = 0; plan->e_argv[cnt]; ++cnt)
-		if (plan->e_len[cnt])
-			brace_subst(plan->e_orig[cnt], &plan->e_argv[cnt],
-			    file, plan->e_len[cnt]);
+	if (plan->flags & F_EXECPLUS) {
+		if ((plan->e_argv[plan->e_ppos] = strdup(file)) == NULL)
+			err(1, NULL);
+		plan->e_len[plan->e_ppos] = strlen(file);
+		plan->e_psize += plan->e_len[plan->e_ppos];
+		if (++plan->e_ppos < plan->e_pnummax &&
+		    plan->e_psize < plan->e_psizemax)
+			return (1);
+		plan->e_argv[plan->e_ppos] = NULL;
+	} else {
+		for (cnt = 0; plan->e_argv[cnt]; ++cnt)
+			if (plan->e_len[cnt])
+				brace_subst(plan->e_orig[cnt],
+				    &plan->e_argv[cnt], file,
+				    plan->e_len[cnt]);
+	}
 
-	if ((plan->flags & F_NEEDOK) && !queryuser(plan->e_argv))
+doexec:	if ((plan->flags & F_NEEDOK) && !queryuser(plan->e_argv))
 		return 0;
 
 	/* make sure find output is interspersed correctly with subprocesses */
@@ -561,6 +581,12 @@ f_exec(plan, entry)
 		warn("%s", plan->e_argv[0]);
 		_exit(1);
 	}
+	if (plan->flags & F_EXECPLUS) {
+		while (--plan->e_ppos >= plan->e_pbnum)
+			free(plan->e_argv[plan->e_ppos]);
+		plan->e_ppos = plan->e_pbnum;
+		plan->e_psize = plan->e_pbsize;
+	}
 	pid = waitpid(pid, &status, 0);
 	return (pid != -1 && WIFEXITED(status) && !WEXITSTATUS(status));
 }
@@ -578,7 +604,8 @@ c_exec(option, argvp)
 	char ***argvp;
 {
 	PLAN *new;			/* node returned */
-	int cnt;
+	long argmax;
+	int cnt, i;
 	char **argv, **ap, *p;
 
 	/* XXX - was in c_execdir, but seems unnecessary!?
@@ -595,12 +622,32 @@ c_exec(option, argvp)
 			    "%s: no terminating \";\"", option->name);
 		if (**ap == ';')
 			break;
+		if (**ap == '+' && ap != argv && strcmp(*(ap - 1), "{}") == 0) {
+			new->flags |= F_EXECPLUS;
+			break;
+		}
 	}
 
 	if (ap == argv)
 		errx(1, "%s: no command specified", option->name);
 
 	cnt = ap - *argvp + 1;
+	if (new->flags & F_EXECPLUS) {
+		new->e_ppos = new->e_pbnum = cnt - 2;
+		if ((argmax = sysconf(_SC_ARG_MAX)) == -1) {
+			warn("sysconf(_SC_ARG_MAX)");
+			argmax = _POSIX_ARG_MAX;
+		}
+		/*
+		 * Estimate the maximum number of arguments as {ARG_MAX}/10,
+		 * and the maximum number of bytes to use for arguments as
+		 * {ARG_MAX}*(3/4).
+		 */
+		new->e_pnummax = argmax / 10;
+		new->e_psizemax = (argmax / 4) * 3;
+		new->e_pbsize = 0;
+		cnt += new->e_pnummax + 1;
+	}
 	if ((new->e_argv = malloc(cnt * sizeof(char *))) == NULL)
 		err(1, NULL);
 	if ((new->e_orig = malloc(cnt * sizeof(char *))) == NULL)
@@ -610,8 +657,11 @@ c_exec(option, argvp)
 
 	for (argv = *argvp, cnt = 0; argv < ap; ++argv, ++cnt) {
 		new->e_orig[cnt] = *argv;
+		if (new->flags & F_EXECPLUS)
+			new->e_pbsize += strlen(*argv) + 1;
 		for (p = *argv; *p; ++p)
-			if (p[0] == '{' && p[1] == '}') {
+			if (!(new->flags & F_EXECPLUS) && p[0] == '{' &&
+			    p[1] == '}') {
 				if ((new->e_argv[cnt] =
 				    malloc(MAXPATHLEN)) == NULL)
 					err(1, NULL);
@@ -623,9 +673,20 @@ c_exec(option, argvp)
 			new->e_len[cnt] = 0;
 		}
 	}
+	if (new->flags & F_EXECPLUS) {
+		new->e_psize = new->e_pbsize;
+		cnt--;
+		for (i = 0; i < new->e_pnummax; i++) {
+			new->e_argv[cnt] = NULL;
+			new->e_len[cnt] = 0;
+			cnt++;
+		}
+		argv = ap;
+		goto done;
+	}
 	new->e_argv[cnt] = new->e_orig[cnt] = NULL;
 
-	*argvp = argv + 1;
+done:	*argvp = argv + 1;
 	return new;
 }