Add unescape() to libutil

formerly known as resolveescapes(), it is of central use to numerous
programs.
This drops a lot of LOC.

Makefile

@@ -54,7 +54,8 @@ LIBUTILSRC =\
 	libutil/strcasestr.c\
 	libutil/strlcat.c\
 	libutil/strlcpy.c\
-	libutil/strsep.c
+	libutil/strsep.c\
+	libutil/unescape.c
 
 LIB = $(LIBUTF) $(LIBUTIL)
 

cut.c

@@ -139,40 +139,6 @@ cut(FILE *fp)
 	}
 }
 
-static size_t
-resolveescapes(char *s, size_t len)
-{
-	size_t i, off, m;
-
-	for (i = 0; i < len; i++) {
-		if (s[i] != '\\')
-			continue;
-		off = 0;
-
-		switch (s[i + 1]) {
-                case '\\': s[i] = '\\'; off++; break;
-                case 'a':  s[i] = '\a'; off++; break;
-                case 'b':  s[i] = '\b'; off++; break;
-                case 'f':  s[i] = '\f'; off++; break;
-                case 'n':  s[i] = '\n'; off++; break;
-                case 'r':  s[i] = '\r'; off++; break;
-                case 't':  s[i] = '\t'; off++; break;
-                case 'v':  s[i] = '\v'; off++; break;
-		case '\0':
-			eprintf("cut: null escape sequence in delimiter\n");
-		default:
-			eprintf("cut: invalid escape sequence '\\%c' in "
-			        "delimiter\n", s[i + 1]);
-		}
-
-		for (m = i + 1; m <= len - off; m++)
-			s[m] = s[m + off];
-		len -= off;
-	}
-
-	return len;
-}
-
 static void
 usage(void)
 {
@@ -197,7 +163,7 @@ main(int argc, char *argv[])
 		delim = EARGF(usage());
 		if (!*delim)
 			eprintf("cut: empty delimiter\n");
-		delimlen = resolveescapes(delim, strlen(delim));
+		delimlen = unescape(delim);
 		break;
 	case 'n':
 		nflag = 1;

libutil/unescape.c

@@ -0,0 +1,50 @@
+/* See LICENSE file for copyright and license details. */
+#include <string.h>
+
+#include "../util.h"
+
+size_t
+unescape(char *s)
+{
+	size_t len, i, off, m, factor, q;
+
+	len = strlen(s);
+
+	for (i = 0; i < len; i++) {
+		if (s[i] != '\\')
+			continue;
+		off = 0;
+
+		switch (s[i + 1]) {
+                case '\\': s[i] = '\\'; off++; break;
+                case 'a':  s[i] = '\a'; off++; break;
+                case 'b':  s[i] = '\b'; off++; break;
+                case 'f':  s[i] = '\f'; off++; break;
+                case 'n':  s[i] = '\n'; off++; break;
+                case 'r':  s[i] = '\r'; off++; break;
+                case 't':  s[i] = '\t'; off++; break;
+                case 'v':  s[i] = '\v'; off++; break;
+		case '\0':
+			eprintf("%s: null escape sequence\n", argv0);
+		default:
+			/* "\O[OO]" octal escape */
+			for (m = i + 1; m < i + 1 + 3 && m < len; m++)
+				if (s[m] < '0' || s[m] > '7')
+					break;
+			if (m == i + 1)
+				eprintf("%s: invalid escape sequence '\\%c'\n", argv0, s[i + 1]);
+			off += m - i - 1;
+			for (--m, q = 0, factor = 1; m > i; m--) {
+				q += (s[m] - '0') * factor;
+				factor *= 8;
+			}
+			s[i] = q;
+		}
+
+		for (m = i + 1; m <= len - off; m++)
+			s[m] = s[m + off];
+		len -= off;
+	}
+
+	return len;
+}

paste.c

@@ -13,42 +13,6 @@ struct fdescr {
 	const char *name;
 };
 
-static size_t
-resolveescapes(char *s)
-{
-        size_t len, i, off, m;
-
-	len = strlen(s);
-
-        for (i = 0; i < len; i++) {
-                if (s[i] != '\\')
-                        continue;
-                off = 0;
-
-                switch (s[i + 1]) {
-                case '\\': s[i] = '\\'; off++; break;
-                case 'a':  s[i] = '\a'; off++; break;
-                case 'b':  s[i] = '\b'; off++; break;
-                case 'f':  s[i] = '\f'; off++; break;
-                case 'n':  s[i] = '\n'; off++; break;
-                case 'r':  s[i] = '\r'; off++; break;
-                case 't':  s[i] = '\t'; off++; break;
-                case 'v':  s[i] = '\v'; off++; break;
-                case '\0':
-                        eprintf("paste: null escape sequence in delimiter\n");
-                default:
-                        eprintf("paste: invalid escape sequence '\\%c' in "
-                                "delimiter\n", s[i + 1]);
-                }
-
-                for (m = i + 1; m <= len - off; m++)
-                        s[m] = s[m + off];
-                len -= off;
-        }
-
-        return len;
-}
-
 static void
 sequential(struct fdescr *dsc, int fdescrlen, Rune *delim, size_t delimlen)
 {
@@ -145,7 +109,7 @@ main(int argc, char *argv[])
 		usage();
 
 	/* populate delimiters */
-	resolveescapes(adelim);
+	unescape(adelim);
 	len = chartorunearr(adelim, &delim);
 
 	/* populate file list */

tr.c

@@ -70,50 +70,6 @@ rstrmatch(Rune *r, char *s, size_t n)
 	return 1;
 }
 
-static size_t
-resolveescapes(Rune *r, size_t len)
-{
-	size_t i, off, m, factor, q;
-
-	for (i = 0; i < len; i++) {
-		if (r[i] != '\\')
-			continue;
-		off = 0;
-
-		switch (r[i + 1]) {
-		case '\\': r[i] = '\\'; off++; break;
-		case 'a':  r[i] = '\a'; off++; break;
-		case 'b':  r[i] = '\b'; off++; break;
-		case 'f':  r[i] = '\f'; off++; break;
-		case 'n':  r[i] = '\n'; off++; break;
-		case 'r':  r[i] = '\r'; off++; break;
-		case 't':  r[i] = '\t'; off++; break;
-		case 'v':  r[i] = '\v'; off++; break;
-		case '\0':
-			eprintf("tr: null escape sequence\n");
-		default:
-			/* "\O[OO]" octal escape */
-			for (m = i + 1; m < i + 1 + 3 && m < len; m++)
-				if (r[m] < '0' || r[m] > '7')
-					break;
-			if (m == i + 1)
-				eprintf("tr: invalid escape sequence '\\%c'\n", r[i + 1]);
-			off += m - i - 1;
-			for (--m, q = 0, factor = 1; m > i; m--) {
-				q += (r[m] - '0') * factor;
-				factor *= 8;
-			}
-			r[i] = q;
-		}
-
-		for (m = i + 1; m <= len - off; m++)
-			r[m] = r[m + off];
-		len -= off;
-	}
-
-	return len;
-}
-
 static size_t
 makeset(char *str, struct range **set, int (**check)(wint_t))
 {
@@ -123,8 +79,8 @@ makeset(char *str, struct range **set, int (**check)(wint_t))
 	int    factor, base;
 
 	/* rstr defines at most len ranges */
+	unescape(str);
 	len = chartorunearr(str, &rstr);
-	len = resolveescapes(rstr, len);
 	*set = emalloc(len * sizeof(**set));
 
 	for (i = 0; i < len; i++) {

util.h

@@ -56,3 +56,4 @@ char *humansize(double);
 mode_t parsemode(const char *, mode_t, mode_t);
 void putword(const char *);
 void recurse(const char *, void (*)(const char *));
+size_t unescape(char *);