ci,build: add version checker helpers

These version helpers were first introduced in Scopy's build.
But we'll need them in libiio to check for Ubuntu 20.04.

Also, centralizing them will make them useful for later.

Signed-off-by: Alexandru Ardelean <[email protected]>

CI/travis/lib.sh

@@ -320,6 +320,28 @@ ensure_command_exists() {
 	return 1
 }
 
+version_gt() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"; }
+version_le() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" = "$1"; }
+version_lt() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" != "$1"; }
+version_ge() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" = "$1"; }
+
+get_codename() {
+	lsb_release -c -s
+}
+
+get_dist_id() {
+	lsb_release -i -s
+}
+
+get_version() {
+	lsb_release -r -s
+}
+
+is_ubuntu_at_least_ver() {
+	[ "$(get_dist_id)" = "Ubuntu" ] || return 1
+	version_ge "$(get_version)" "$1"
+}
+
 print_github_api_rate_limits() {
 	# See https://developer.github.com/v3/rate_limit/
 	# Note: Accessing this endpoint does not count against your REST API rate limit.