wc: Clean up and modernize.

* Drop <err.h>, which is unnecessary since we use libxo.

* As per POSIX, report an error if output fails.

* Fix some type mismatches.

* Use bool instead of int where appropriate.

* Avoid repeatedly checking for a null filename.

* Miscellaneous other tidying.

* Add tests (partly derived from work performed by SHENG-YI HONG <[email protected]>).

Sponsored by:	Klara, Inc.
Reviewed by:	kevans
Differential Revision:	https://reviews.freebsd.org/D38496

etc/mtree/BSD.tests.dist

@@ -1120,6 +1120,8 @@
         ..
         vmstat
         ..
+        wc
+        ..
         xargs
         ..
         xinstall

usr.bin/wc/Makefile

@@ -12,4 +12,7 @@ LIBADD+=        cap_fileargs
 CFLAGS+=-DWITH_CASPER
 .endif
 
+HAS_TESTS=
+SUBDIR.${MK_TESTS}=	tests
+
 .include <bsd.prog.mk>

usr.bin/wc/tests/Makefile

@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+PACKAGE=	tests
+
+ATF_TESTS_SH=	wc_test
+BINDIR=		${TESTSDIR}
+
+.include <bsd.test.mk>

usr.bin/wc/tests/wc_test.sh

@@ -0,0 +1,197 @@
+#
+# Copyright (c) 2023 Klara, Inc.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+#
+# These tests need to run in a multibyte locale with non-localized
+# error messages.
+#
+export LC_CTYPE=C.UTF-8
+export LC_MESSAGES=C
+
+#
+# Sample text containing multibyte characters
+#
+tv="Der bode en underlig gråsprængt en
+på den yderste nøgne ø; –
+han gjorde visst intet menneske mén
+hverken på land eller sjø;
+dog stundom gnistred hans øjne stygt, –
+helst mod uroligt vejr, –
+og da mente folk, at han var forrykt,
+og da var der få, som uden frykt
+kom Terje Vigen nær.
+"
+tvl=10
+tvw=55
+tvc=300
+tvm=283
+tvcL=42
+tvmL=39
+
+#
+# Run a series of tests using the same input file.  The first argument
+# is the name of the file.  The next three are the expected line,
+# word, and byte counts.  The optional fifth is the expected character
+# count; if not provided, it is expected to be identical to the byte
+# count.
+#
+atf_check_wc() {
+	local file="$1"
+	local l="$2"
+	local w="$3"
+	local c="$4"
+	local m="${5-$4}"
+
+	atf_check -o match:"^ +${l} +${w} +${c}\$" wc <"${file}"
+	atf_check -o match:"^ +${l}\$" wc -l <"${file}"
+	atf_check -o match:"^ +${w}\$" wc -w <"${file}"
+	atf_check -o match:"^ +${c}\$" wc -c <"${file}"
+	atf_check -o match:"^ +${m}\$" wc -m <"${file}"
+	atf_check -o match:"^ +${l} +${w} +${c} ${file}\$" wc "$file"
+	atf_check -o match:"^ +${l} ${file}\$" wc -l "$file"
+	atf_check -o match:"^ +${w} ${file}\$" wc -w "$file"
+	atf_check -o match:"^ +${c} ${file}\$" wc -c "$file"
+	atf_check -o match:"^ +${m} ${file}\$" wc -m "$file"
+}
+
+atf_test_case basic
+basic_head()
+{
+	atf_set "descr" "Basic test case"
+}
+basic_body()
+{
+	printf "a b\n" >foo
+	atf_check_wc foo 1 2 4
+}
+
+atf_test_case blank
+blank_head()
+{
+	atf_set "descr" "Input containing only blank lines"
+}
+blank_body()
+{
+	printf "\n\n\n" >foo
+	atf_check_wc foo 3 0 3
+}
+
+atf_test_case empty
+empty_head()
+{
+	atf_set "descr" "Empty input"
+}
+empty_body()
+{
+	printf "" >foo
+	atf_check_wc foo 0 0 0
+}
+
+atf_test_case invalid
+invalid_head()
+{
+	atf_set "descr" "Invalid multibyte input"
+}
+invalid_body()
+{
+	printf "a\377b\n" >foo
+	atf_check \
+	    -e match:"Illegal byte sequence" \
+	    -o match:"^ +4 foo$" \
+	    wc -m foo
+}
+
+atf_test_case multiline
+multiline_head()
+{
+	atf_set "descr" "Multiline, multibyte input"
+}
+multiline_body()
+{
+	printf "%s\n" "$tv" >foo
+	atf_check_wc foo $tvl $tvw $tvc $tvm
+	# longest line in bytes
+	atf_check -o match:"^ +$tvc +$tvcL foo" wc -cL foo
+	atf_check -o match:"^ +$tvc +$tvcL" wc -cL <foo
+	# longest line in characters
+	atf_check -o match:"^ +$tvm +$tvmL foo" wc -mL foo
+	atf_check -o match:"^ +$tvm +$tvmL" wc -mL <foo
+}
+
+atf_test_case multiline_repeated
+multiline_repeated_head()
+{
+	atf_set "descr" "Multiline input exceeding the input buffer size"
+}
+multiline_repeated_body()
+{
+	local c=0
+	while [ $c -lt 1000 ] ; do
+		printf "%1\$s\n%1\$s\n%1\$s\n%1\$s\n%1\$s\n" "$tv"
+		c=$((c+5))
+	done >foo
+	atf_check_wc foo $((tvl*c)) $((tvw*c)) $((tvc*c)) $((tvm*c))
+}
+
+atf_test_case total
+total_head()
+{
+	atf_set "descr" "Multiple inputs"
+}
+total_body()
+{
+	printf "%s\n" "$tv" >foo
+	printf "%s\n" "$tv" >bar
+	atf_check \
+	    -o match:"^ +$((tvl*2)) +$((tvw*2)) +$((tvc*2)) total$" \
+	    wc foo bar
+}
+
+atf_test_case unterminated
+unterminated_head()
+{
+	atf_set "descr" "Input not ending in newline"
+}
+unterminated_body()
+{
+	printf "a b" >foo
+	atf_check_wc foo 0 2 3
+}
+
+atf_test_case usage
+usage_head()
+{
+	atf_set "descr" "Trigger usage message"
+}
+usage_body()
+{
+	atf_check -s exit:1 -e match:"usage: wc" wc -\?
+}
+
+atf_test_case whitespace
+whitespace_head()
+{
+	atf_set "descr" "Input containing only whitespace and newlines"
+}
+whitespace_body()
+{
+	printf "\n \n\t\n" >foo
+	atf_check_wc foo 3 0 5
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case basic
+	atf_add_test_case blank
+	atf_add_test_case empty
+	atf_add_test_case invalid
+	atf_add_test_case multiline
+	atf_add_test_case multiline_repeated
+	atf_add_test_case total
+	atf_add_test_case unterminated
+	atf_add_test_case usage
+	atf_add_test_case whitespace
+}