Sync with FreeBSD's xargs plus some fixes by me. This makes us

POSIX-compliant and adds some useful extensions.  Most of the work
in FreeBSD was done by jmallett.

1 files changed, 100 insertions, 0 deletions

diff --git a/usr.bin/xargs/strnsubst.c b/usr.bin/xargs/strnsubst.c
new file mode 100644
index 00000000000..01405717ba4
--- /dev/null
+++ b/usr.bin/xargs/strnsubst.c
@@ -0,0 +1,100 @@
+/*	$OpenBSD: strnsubst.c,v 1.1 2003/06/12 01:09:23 millert Exp $	*/
+/*	$FreeBSD: strnsubst.c,v 1.6 2002/06/22 12:58:42 jmallett Exp $	*/
+
+/*
+ * Copyright (c) 2002 J. Mallett.  All rights reserved.
+ * You may do whatever you want with this file as long as
+ * the above copyright and this notice remain intact, along
+ * with the following statement:
+ * 	For the man who taught me vi, and who got too old, too young.
+ */
+
+#ifndef lint
+static const char rcsid[] = "$OpenBSD: strnsubst.c,v 1.1 2003/06/12 01:09:23 millert Exp $";
+#endif /* not lint */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+void	strnsubst(char **, const char *, const char *, size_t);
+
+/*
+ * Replaces str with a string consisting of str with match replaced with
+ * replstr as many times as can be done before the constructed string is
+ * maxsize bytes large.  It does not free the string pointed to by str, it
+ * is up to the calling program to be sure that the original contents of
+ * str as well as the new contents are handled in an appropriate manner.
+ * If replstr is NULL, then that internally is changed to a nil-string, so
+ * that we can still pretend to do somewhat meaningful substitution.
+ * No value is returned.
+ */
+void
+strnsubst(char **str, const char *match, const char *replstr, size_t maxsize)
+{
+	char *s1, *s2, *this;
+	size_t matchlen, repllen, s2len, n;
+
+	if ((s1 = *str) == NULL)
+		return;
+	if ((s2 = malloc(maxsize)) == NULL)
+		err(1, NULL);
+
+	if (replstr == NULL)
+		replstr = "";
+
+	if (match == NULL || *match == '\0' || strlen(s1) >= maxsize) {
+		strlcpy(s2, s1, maxsize);
+		goto done;
+	}
+
+	*s2 = '\0';
+	s2len = 0;
+	matchlen = strlen(match);
+	repllen = strlen(replstr);
+	for (;;) {
+		if ((this = strstr(s1, match)) == NULL)
+			break;
+		n = snprintf(s2 + s2len, maxsize - s2len, "%.*s%s",
+		    (int)(this - s1), s1, replstr);
+		if (n + s2len + strlen(this + matchlen) >= maxsize)
+			break;			/* out of room */
+		s2len += n;
+		s1 = this + matchlen;
+	}
+	strlcpy(s2 + s2len, s1, maxsize - s2len);
+done:
+	*str = s2;
+	return;
+}
+
+#ifdef TEST
+#include <stdio.h>
+
+int 
+main(void)
+{
+	char *x, *y, *z, *za;
+
+	x = "{}%$";
+	strnsubst(&x, "%$", "{} enpury!", 255);
+	y = x;
+	strnsubst(&y, "}{}", "ybir", 255);
+	z = y;
+	strnsubst(&z, "{", "v ", 255);
+	za = z;
+	strnsubst(&z, NULL, za, 255);
+	if (strcmp(z, "v ybir enpury!") == 0)
+		printf("strnsubst() seems to work!\n");
+	else
+		printf("strnsubst() is broken.\n");
+	printf("%s\n", z);
+	free(x);
+	free(y);
+	free(z);
+	free(za);
+	return 0;
+}
+#endif