From 2c4f022eddb11b0fd4e164a6fdae169b008f2371 Mon Sep 17 00:00:00 2001
From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Thu, 4 Jul 2019 01:50:02 -0400
Subject: [PATCH] Add bt_common_get_term_size()

Using ioctl() instead of the `COLUMNS` environment variable because
`COLUMNS` is in fact a shell variable which is not exported.

The function is not supported on Windows yet.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Change-Id: I84942830f0392ff1aca3e1aff54fffc534ddda05
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1621
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Francis Deslauriers <francis.deslauriers@efficios.com>
---
 src/common/common.c | 33 +++++++++++++++++++++++++++++++++
 src/common/common.h |  7 +++++++
 2 files changed, 40 insertions(+)

diff --git a/src/common/common.c b/src/common/common.c
index aef36b28..ed1d1c27 100644
--- a/src/common/common.c
+++ b/src/common/common.c
@@ -46,6 +46,7 @@
 
 #ifndef __MINGW32__
 #include <pwd.h>
+#include <sys/ioctl.h>
 #endif
 
 #define SYSTEM_PLUGIN_PATH	INSTALL_LIBDIR "/babeltrace2/plugins"
@@ -1791,3 +1792,35 @@ end:
 
 	return folded;
 }
+
+#ifdef __MINGW32__
+BT_HIDDEN
+int bt_common_get_term_size(unsigned int *width, unsigned int *height)
+{
+	/* Not supported on Windows yet */
+	return -1;
+}
+#else /* __MINGW32__ */
+BT_HIDDEN
+int bt_common_get_term_size(unsigned int *width, unsigned int *height)
+{
+	int ret = 0;
+	struct winsize winsize;
+
+	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) < 0) {
+		ret = -1;
+		goto end;
+	}
+
+	if (width) {
+		*width = (unsigned int) winsize.ws_col;
+	}
+
+	if (height) {
+		*height = (unsigned int) winsize.ws_row;
+	}
+
+end:
+	return ret;
+}
+#endif /* __MINGW32__ */
diff --git a/src/common/common.h b/src/common/common.h
index 0f2736f0..1b952913 100644
--- a/src/common/common.h
+++ b/src/common/common.h
@@ -348,6 +348,13 @@ BT_HIDDEN
 GString *bt_common_fold(const char *str, unsigned int total_length,
 		unsigned int indent);
 
+/*
+ * Writes the terminal's width to `*width`, its height to `*height`,
+ * and returns 0 on success, or returns -1 on error.
+ */
+BT_HIDDEN
+int bt_common_get_term_size(unsigned int *width, unsigned int *height);
+
 /*
  * Wraps read() function to handle EINTR and partial reads.
  * On success, it returns `count` received as parameter. On error, it returns a
-- 
2.34.1