Add grammar checking script

A Markdown parser will eventually be added to prevent
language_tool_python from grammar checking markup.

Also the output will be reduced to just the errors and the script will
not prompt for confirmation if no errors are detected. Currently, it
always prompts.

1 files changed, 30 insertions, 0 deletions

diff --git a/hooks/pre-commit b/hooks/pre-commit
new file mode 100755
index 0000000..317ed48
--- /dev/null
+++ b/hooks/pre-commit
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+# automatically configured by git-annex
+git annex pre-commit .
+
+# check grammar of staged Markdown files
+check_grammar() {
+    # get list of staged Markdown files (added or modified)
+    staged_files=$(git diff --cached --name-only --diff-filter=AM | grep '\.md$')
+
+    [ -z "$staged_files" ] && return 0
+
+    printf "Checking grammar of staged files.\n"
+    language_tool_python --picky $staged_files
+
+    printf "Proceed with commit? (y/n): "
+    read yn < /dev/tty
+
+    [ "$yn" == "${yn#[Yy]}" ] && return 1
+
+    return 0
+}
+
+# run grammar check
+check_grammar
+
+if [ $? -ne 0 ]; then
+    printf "Aborted.\n"
+    exit 1
+fi