[GSoC][RFC/PATCH] userdiff: added support for diffing shell scripts

[Kapil Jain <jkapil.cs@gmail.com>]

Signed-off-by: Kapil Jain <jkapil.cs@gmail.com>
---

The test written does not pass, imo there's some problem with the regex part.
please let me know about the fault.

 t/t4034-diff-words.sh | 2 ++
 t/t4034/shell/expect  | 6 ++++++
 t/t4034/shell/post    | 1 +
 t/t4034/shell/pre     | 1 +
 userdiff.c            | 7 +++++++
 5 files changed, 17 insertions(+)
 create mode 100644 t/t4034/shell/expect
 create mode 100644 t/t4034/shell/post
 create mode 100644 t/t4034/shell/pre

diff --git a/t/t4034-diff-words.sh b/t/t4034-diff-words.sh
index 912df91226..74366e6826 100755
--- a/t/t4034-diff-words.sh
+++ b/t/t4034-diff-words.sh
@@ -314,6 +314,8 @@ test_language_driver php
 test_language_driver python
 test_language_driver ruby
 test_language_driver tex
+test_language_driver shell
+
 
 test_expect_success 'word-diff with diff.sbe' '
 	cat >expect <<-\EOF &&
diff --git a/t/t4034/shell/expect b/t/t4034/shell/expect
new file mode 100644
index 0000000000..f2f65e7a9b
--- /dev/null
+++ b/t/t4034/shell/expect
@@ -0,0 +1,6 @@
+<BOLD>diff --git a/pre b/post<RESET>
+<BOLD>index 2fc00ad..cd34305 100644<RESET>
+<BOLD>--- a/pre<RESET>
+<BOLD>+++ b/post<RESET>
+<CYAN>@@ -1 +1 @@<RESET>
+<RED>[-$TEST_DIRECTORY-]<RESET><GREEN>{+$TEST_DIR+}<RESET>
diff --git a/t/t4034/shell/post b/t/t4034/shell/post
new file mode 100644
index 0000000000..43a84e0188
--- /dev/null
+++ b/t/t4034/shell/post
@@ -0,0 +1 @@
+$TEST_DIR
diff --git a/t/t4034/shell/pre b/t/t4034/shell/pre
new file mode 100644
index 0000000000..32440f90b7
--- /dev/null
+++ b/t/t4034/shell/pre
@@ -0,0 +1 @@
+$TEST_DIRECTORY
diff --git a/userdiff.c b/userdiff.c
index 3a78fbf504..936447a0bc 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -158,6 +158,13 @@ PATTERNS("csharp",
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
 	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
+
+PATTERNS("shell",
+  /* Function Names */
+  "([A-Za-z_][A-Za-z0-9_]*)[[:space:]]*\\([[:space:]]*\\)[[:space:]]*\\{",
+  /* Words */
+  "([$#@A-Za-z_\"\'][$#@A-Za-z0-9_\"\']*)"),
+
 IPATTERN("css",
 	 "![:;][[:space:]]*$\n"
 	 "^[_a-z0-9].*$",
-- 
2.14.2