Port grep() and ls() to POSIX sh

Check capabilities of wrapped programs at runtime, not declaration time.
Also do away with the silly GREP_COLORS and GREP_OPTS variables.
Considering doing the same with LS_COLORS.

1 files changed, 35 insertions, 0 deletions

diff --git a/sh/shrc.d/grep.sh b/sh/shrc.d/grep.sh
new file mode 100644
index 00000000..df2101aa
--- /dev/null
+++ b/sh/shrc.d/grep.sh
@@ -0,0 +1,35 @@
+# Our ~/.profile should already have made a directory with the supported
+# options for us; if not, we won't be wrapping grep(1) with a function at all
+[ -d "$HOME"/.cache/grep ] || return
+
+# Define function proper
+grep() {
+
+    # Add --color if the terminal has at least 8 colors
+    [ -e "$HOME"/.cache/grep/color ] &&
+    [ "$({ tput colors || tput Co ; } 2>/dev/null)" -ge 8 ] &&
+        set -- --color=auto "$@"
+
+    # Add --binary-files=without-match to gracefully skip binary files
+    [ -e "$HOME"/.cache/grep/binary-files ] &&
+        set -- --binary-files=without-match "$@"
+
+    # Add --exclude to ignore .gitignore and .gitmodules files
+    [ -e "$HOME"/.cache/grep/exclude ] &&
+        set -- \
+            --exclude=.gitignore  \
+            --exclude=.gitmodules \
+            "$@"
+
+    # Add --exclude-dir to ignore version control dot-directories
+    [ -e "$HOME"/.cache/grep/exclude-dir ] &&
+        set -- \
+            --exclude-dir=.cvs \
+            --exclude-dir=.git \
+            --exclude-dir=.hg  \
+            --exclude-dir=.svn \
+            "$@"
+
+    # Run grep(1) with the concluded arguments
+    command grep "$@"
+}