1 files changed, 27 insertions, 0 deletions
diff --git a/sh/lib.sh/existence.sh b/sh/lib.sh/existence.sh
new file mode 100644
index 0000000..a888dee
--- /dev/null
+++ b/sh/lib.sh/existence.sh
@@ -0,0 +1,27 @@
+# This file is part of TALER
+# (C) 2019 GNUnet e.V.
+#
+# Authors:
+# Author: ng0 <ng0@taler.net>
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE
+# LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
+# OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+# ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+# THIS SOFTWARE.
+#
+# SPDX-License-Identifier: 0BSD
+
+# there is a function used in curl to replicate which(1), but
+# it uses too many other tools. this one uses command and in
+# gnunet so far has no reports about failures.
+existence()
+{
+    command -v "$1" >/dev/null 2>&1
+}