From: Karel Zak <kzak@redhat.com>
Date: Wed, 9 Mar 2016 14:51:28 +0000 (+0100)
Subject: look: consider blanks as directory characters
X-Git-Tag: v2.28-rc1~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b480fe67b0641cd8dbb0ef3cedb7c4666f5b209;p=thirdparty%2Futil-linux.git

look: consider blanks as directory characters

This change introduces regression, but it seems better than to be
incompatible with "sort -d" if we assume that "sort -d" is the right
way how to prepare files for look(1).

It seems (from man page) that the original goal has been compatibility
with sort -d, but this feature has never been fully implemented.

Addresses: https://github.com/karelzak/util-linux/issues/284
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/misc-utils/look.1 b/misc-utils/look.1
index e96a4318dc..4de5f0ed7b 100644
--- a/misc-utils/look.1
+++ b/misc-utils/look.1
@@ -68,12 +68,16 @@ alphabetic characters is ignored.
 Use the alternative dictionary file.
 .TP
 .BR \-d , " \-\-alphanum"
-Use normal dictionary character set and order, i.e. only alphanumeric characters
-are compared.  (This is on by default if no file is specified.)
+Use normal dictionary character set and order, i.e. only blanks and
+alphanumeric characters are compared.  This is on by default if no file is
+specified.
+
+Note that blanks have been added to dictionary character set for
+compatibility with \fBsort \-d\fR command since version 2.28.
 .TP
 .BR \-f , " \-\-ignore\-case"
-Ignore the case of alphabetic characters.  (This is on by default if no file is
-specified.)
+Ignore the case of alphabetic characters.  This is on by default if no file is
+specified.
 .TP
 .BR \-t , " \-\-terminate " \fIcharacter\fR
 Specify a string termination character, i.e. only the characters
@@ -105,10 +109,6 @@ the alternative dictionary
 .SH "SEE ALSO"
 .BR grep (1),
 .BR sort (1)
-.SH COMPATIBILITY
-The original manual page stated that tabs and blank characters participated
-in comparisons when the \fB\-\-alphanum\fR option was specified.  This was
-incorrect, and the current man page matches the historic implementation.
 .SH HISTORY
 The
 .B look
diff --git a/misc-utils/look.c b/misc-utils/look.c
index 96a02c41d7..f0cc1d7f19 100644
--- a/misc-utils/look.c
+++ b/misc-utils/look.c
@@ -174,7 +174,7 @@ look(char *front, char *back)
 	/* Reformat string string to avoid doing it multiple times later. */
 	if (dflag) {
 		for (readp = writep = string; (ch = *readp++) != 0;) {
-			if (isalnum(ch))
+			if (isalnum(ch) || isblank(ch))
 				*(writep++) = ch;
 		}
 		*writep = '\0';
@@ -333,7 +333,7 @@ compare(char *s2, char *s2end) {
 	p = comparbuf;
 	i = stringlen;
 	while(s2 < s2end && *s2 != '\n' && i) {
-		if (!dflag || isalnum(*s2))
+		if (!dflag || isalnum(*s2) || isblank(*s2))
 		{
 			*p++ = *s2;
 			i--;
@@ -361,7 +361,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 
 	fputs(USAGE_OPTIONS, out);
 	fputs(_(" -a, --alternative        use the alternative dictionary\n"), out);
-	fputs(_(" -d, --alphanum           compare only alphanumeric characters\n"), out);
+	fputs(_(" -d, --alphanum           compare only blanks and alphanumeric characters\n"), out);
 	fputs(_(" -f, --ignore-case        ignore case differences when comparing\n"), out);
 	fputs(_(" -t, --terminate <char>   define the string-termination character\n"), out);