Add tig-pick script

Signed-off-by: Konrad Gräfe <[email protected]>

contrib/tig-pick

@@ -0,0 +1,48 @@
+#!/bin/sh
+#
+# 'tig-pick' is a wrapper script that uses 'tig' to pick a Git commit from the
+# history. On success, The script prints the ID of the commit to standard
+# output, so that it can be used as a parameter for subsequent commands, e.g.
+# 'git rebase -i $(tig-pick)'
+#
+# In order to be able to display the interface and to catch the commit ID
+# (easily) at the same time, 'tig' has to be run with the standard and error
+# output channels swapped.
+#
+# All parameters passed to the script will be forwarded to 'tig'.
+#
+
+
+set -e
+
+CONFIG=$(mktemp)
+trap "rm -f '$CONFIG'" EXIT
+
+# Prepare config file: source user config, if present
+if [ ! -z "$TIGRC_USER" ]; then
+	echo "source $TIGRC_USER" >> $CONFIG
+elif [ -f "$HOME/.tigrc" ]; then
+	echo "source $HOME/.tigrc" >> $CONFIG
+fi
+
+# Bind Enter to print the selected commit ID to error output and exit after
+# that.
+echo 'bind main <Enter> <sh -c "echo %(commit) >&2"' >> $CONFIG
+
+
+# Run tig with the standard and error output channels swapped.
+export TIGRC_USER=$CONFIG
+stderr=$(tig "$@" 3>&2 2>&1 1>&3 3>&-) || {
+	status=$?
+	echo "$stderr" >&2
+	exit $status
+}
+commit=$(echo "$stderr" | tail -n1)
+
+# Check return value for valid commit ID
+if ! echo -n "$commit" | grep -iqE '^[0-9a-f]{40}$'; then
+	echo "$stderr" >&2
+	exit 1
+fi
+
+echo "$commit"