lib/colors: use libtinfo to check terminal capability

The current implementation assumes that all terminals supports colors
and users are forcet to use terminal-colors.d/ to disable colors for
some terminals.

This patch checks for maximal supported colors for the current
terminal and colors are automatically disabled for terminals like
vt100.

The patch moves lib/colors.c from libcommon.la to libtcolors.la to
avoid collisions with another utils.

Signed-off-by: Karel Zak <kzak@redhat.com>

8 files changed, 57 insertions, 13 deletions

diff --git a/configure.ac b/configure.ac
index 122b5d532..f7c3f8e57 100644
--- a/configure.ac
+++ b/configure.ac
@@ -778,6 +778,9 @@ PKG_CHECK_MODULES(TINFO, [tinfo], [have_tinfo=yes], [
 AC_SUBST([TINFO_LIBS])
 AC_SUBST([TINFO_CFLAGS])
 AM_CONDITIONAL([HAVE_TINFO], [test "x$have_tinfo" = xyes])
+AS_IF([test "x$have_tinfo" = xyes],
+	AC_DEFINE(HAVE_LIBTINFO, 1, [Define if libtinfo available.])
+])
 
 
 AC_ARG_WITH([utempter],
diff --git a/disk-utils/Makemodule.am b/disk-utils/Makemodule.am
index b4606a148..766b40bcc 100644
--- a/disk-utils/Makemodule.am
+++ b/disk-utils/Makemodule.am
@@ -134,7 +134,7 @@ fdisk_SOURCES = \
 	disk-utils/fdisk-list.c \
 	disk-utils/fdisk-list.h
 
-fdisk_LDADD = $(LDADD) libcommon.la libfdisk.la libsmartcols.la
+fdisk_LDADD = $(LDADD) libcommon.la libfdisk.la libsmartcols.la libtcolors.la
 fdisk_CFLAGS = $(AM_CFLAGS) -I$(ul_libfdisk_incdir) -I$(ul_libsmartcols_incdir)
 
 if BUILD_LIBBLKID
@@ -166,7 +166,7 @@ sfdisk_SOURCES = \
 	disk-utils/fdisk-list.c \
 	disk-utils/fdisk-list.h
 
-sfdisk_LDADD = $(LDADD) libcommon.la libfdisk.la libsmartcols.la
+sfdisk_LDADD = $(LDADD) libcommon.la libfdisk.la libsmartcols.la libtcolors.la
 sfdisk_CFLAGS = $(AM_CFLAGS) -I$(ul_libfdisk_incdir) -I$(ul_libsmartcols_incdir)
 
 if BUILD_LIBUUID
@@ -193,7 +193,7 @@ if BUILD_CFDISK
 sbin_PROGRAMS += cfdisk
 dist_man_MANS += disk-utils/cfdisk.8
 cfdisk_SOURCES = disk-utils/cfdisk.c
-cfdisk_LDADD = $(LDADD) libcommon.la libfdisk.la
+cfdisk_LDADD = $(LDADD) libcommon.la libfdisk.la libtcolors.la
 cfdisk_CFLAGS = $(AM_CFLAGS) -I$(ul_libfdisk_incdir)
 
 if BUILD_LIBUUID
diff --git a/lib/Makemodule.am b/lib/Makemodule.am
index 565294e5c..a33f0a089 100644
--- a/lib/Makemodule.am
+++ b/lib/Makemodule.am
@@ -5,7 +5,6 @@ libcommon_la_SOURCES = \
 	lib/at.c \
 	lib/blkdev.c \
 	lib/canonicalize.c \
-	lib/colors.c \
 	lib/crc32.c \
 	lib/crc64.c \
 	lib/env.c \
@@ -41,8 +40,15 @@ if HAVE_CPU_SET_T
 libcommon_la_SOURCES += lib/cpuset.c
 endif
 
+
+noinst_LTLIBRARIES += libtcolors.la
+libtcolors_la_CFLAGS = $(AM_CFLAGS) $(TINFO_CFLAGS)
+libtcolors_la_LIBADD = $(TINFO_LIBS)
+libtcolors_la_SOURCES = lib/colors.c include/colors.h
+
 dist_man_MANS += lib/terminal-colors.d.5
 
+
 check_PROGRAMS += \
 	test_at \
 	test_blkdev \
@@ -56,6 +62,9 @@ check_PROGRAMS += \
 	test_strutils \
 	test_ttyutils
 
+
+
+
 if LINUX
 if HAVE_CPU_SET_T
 check_PROGRAMS += test_cpuset
@@ -87,7 +96,8 @@ test_strutils_SOURCES = lib/strutils.c
 test_strutils_CFLAGS = -DTEST_PROGRAM
 
 test_colors_SOURCES = lib/colors.c
-test_colors_CFLAGS = -DTEST_PROGRAM
+test_colors_CFLAGS = -DTEST_PROGRAM $(TINFO_CFLAGS)
+test_colors_LDADD = $(LDADD) $(TINFO_LIBS)
 
 test_randutils_SOURCES = lib/randutils.c
 test_randutils_CFLAGS = -DTEST_PROGRAM
diff --git a/lib/colors.c b/lib/colors.c
index 2e5af48d9..da5a3e1f4 100644
--- a/lib/colors.c
+++ b/lib/colors.c
@@ -10,6 +10,10 @@
 #include <sys/types.h>
 #include <dirent.h>
 #include <ctype.h>
+#ifdef HAVE_LIBTINFO
+# include <curses.h>
+# include <term.h>
+#endif
 
 #include "c.h"
 #include "colors.h"
@@ -664,6 +668,31 @@ static void termcolors_init_debug(void)
 	__UL_INIT_DEBUG(termcolors, TERMCOLORS_DEBUG_, 0, TERMINAL_COLORS_DEBUG);
 }
 
+static int colors_terminal_is_ready(void)
+{
+	int ncolors = -1;
+
+	if (isatty(STDOUT_FILENO) != 1)
+		goto none;
+
+#ifdef HAVE_LIBTINFO
+	{
+		int ret;
+
+		if (setupterm(NULL, STDOUT_FILENO, &ret) != OK || ret != 1)
+			goto none;
+		ncolors = tigetnum("colors");
+		if (ncolors <= 2)
+			goto none;
+	}
+#endif
+	DBG(CONF, ul_debug("terminal is ready (supports %d colors)", ncolors));
+	return 1;
+none:
+	DBG(CONF, ul_debug("terminal is NOT ready"));
+	return 0;
+}
+
 /**
  * colors_init:
  * @mode: UL_COLORMODE_*
@@ -676,7 +705,7 @@ static void termcolors_init_debug(void)
  */
 int colors_init(int mode, const char *name)
 {
-	int atty = -1;
+	int ready = -1;
 	struct ul_color_ctl *cc = &ul_colors;
 
 	cc->utilname = name;
@@ -684,7 +713,7 @@ int colors_init(int mode, const char *name)
 
 	termcolors_init_debug();
 
-	if (mode == UL_COLORMODE_UNDEF && (atty = isatty(STDOUT_FILENO))) {
+	if (mode == UL_COLORMODE_UNDEF && (ready = colors_terminal_is_ready())) {
 		int rc = colors_read_configuration(cc);
 		if (rc)
 			cc->mode = UL_COLORMODE_DEFAULT;
@@ -703,7 +732,7 @@ int colors_init(int mode, const char *name)
 
 	switch (cc->mode) {
 	case UL_COLORMODE_AUTO:
-		cc->has_colors = atty == -1 ? isatty(STDOUT_FILENO) : atty;
+		cc->has_colors = ready == -1 ? colors_terminal_is_ready() : ready;
 		break;
 	case UL_COLORMODE_ALWAYS:
 		cc->has_colors = 1;
diff --git a/libsmartcols/src/Makemodule.am b/libsmartcols/src/Makemodule.am
index c1facad0c..49ffea65f 100644
--- a/libsmartcols/src/Makemodule.am
+++ b/libsmartcols/src/Makemodule.am
@@ -22,7 +22,7 @@ libsmartcols_la_SOURCES= \
 
 nodist_libsmartcols_la_SOURCES = libsmartcols/src/smartcolsP.h
 
-libsmartcols_la_LIBADD = libcommon.la
+libsmartcols_la_LIBADD = libcommon.la libtcolors.la
 
 libsmartcols_la_CFLAGS = \
 	$(SOLIB_CFLAGS) \
@@ -31,6 +31,7 @@ libsmartcols_la_CFLAGS = \
 
 libsmartcols_la_DEPENDENCIES = \
 	libcommon.la \
+	libtcolors.la \
 	libsmartcols/src/libsmartcols.sym \
 	libsmartcols/src/libsmartcols.h.in
 
@@ -48,7 +49,7 @@ if BUILD_LIBSMARTCOLS_TESTS
 check_PROGRAMS += test_smartcols
 
 libsmartcols_tests_cflags = $(libsmartcols_la_CFLAGS)
-libsmartcols_tests_ldadd  = libsmartcols.la libcommon.la
+libsmartcols_tests_ldadd  = libsmartcols.la libcommon.la libtcolors.la
 
 test_smartcols_SOURCES = libsmartcols/src/test.c
 test_smartcols_CFLAGS = $(libsmartcols_tests_cflags)
diff --git a/misc-utils/Makemodule.am b/misc-utils/Makemodule.am
index 3c79bec53..f7485c958 100644
--- a/misc-utils/Makemodule.am
+++ b/misc-utils/Makemodule.am
@@ -11,7 +11,7 @@ cal_SOURCES += lib/langinfo.c
 endif
 
 cal_CFLAGS = $(AM_CFLAGS) $(NCURSES_CFLAGS)
-cal_LDADD = $(LDADD) libcommon.la $(NCURSES_LIBS) $(TINFO_LIBS)
+cal_LDADD = $(LDADD) libcommon.la libtcolors.la $(NCURSES_LIBS)
 if HAVE_TERMCAP
 cal_LDADD += -ltermcap
 endif
diff --git a/sys-utils/Makemodule.am b/sys-utils/Makemodule.am
index 23b8f5c0c..8e6108d07 100644
--- a/sys-utils/Makemodule.am
+++ b/sys-utils/Makemodule.am
@@ -73,7 +73,8 @@ if BUILD_DMESG
 bin_PROGRAMS += dmesg
 dist_man_MANS += sys-utils/dmesg.1
 dmesg_SOURCES = sys-utils/dmesg.c lib/monotonic.c
-dmesg_LDADD = $(LDADD) libcommon.la $(CLOCKGETTIME_LIBS)
+dmesg_LDADD = $(LDADD) libcommon.la libtcolors.la $(CLOCKGETTIME_LIBS)
+dmesg_CFLAGS = $(AM_CFLAGS)
 endif
 
 if BUILD_CTRLALTDEL
diff --git a/text-utils/Makemodule.am b/text-utils/Makemodule.am
index bd3d53f82..94c8c7e05 100644
--- a/text-utils/Makemodule.am
+++ b/text-utils/Makemodule.am
@@ -34,7 +34,7 @@ hexdump_SOURCES = \
 	text-utils/hexdump.c \
 	text-utils/hexdump.h \
 	text-utils/hexdump-parse.c
-hexdump_LDADD = $(LDADD) libcommon.la
+hexdump_LDADD = $(LDADD) libcommon.la libtcolors.la
 endif
 
 if BUILD_REV