1 files changed, 93 insertions, 0 deletions
diff --git a/unix/link_dup.sh b/unix/link_dup.sh
new file mode 100755
index 0000000..ec54530
--- /dev/null
+++ b/unix/link_dup.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+#
+# Replace duplicate files with symbolic links.
+#
+# <dup_list> format (dup* will be removed and linked to FILE):
+# FILE dup1 dup2 ...
+#
+# NOTE:
+# * Filename cannot contain spaces.
+#
+# Weitian LI
+# 2015/03/06
+#
+
+err_msg() {
+    echo "$@" > /dev/stderr
+}
+
+usage() {
+    err_msg "Usage:"
+    err_msg "    $1 <dup_list>"
+}
+
+md5() {
+    file="$1"
+    os=`uname -s`
+    case "${os}" in
+        Linux)
+            MD5=`md5sum ${file} | awk '{ print $1 }'`
+            ;;
+        FreeBSD)
+            MD5=`md5 ${file} | awk '{ print $NF }'`
+            ;;
+        *)
+            err_msg "ERROR: Unsupported OS: ${os}"
+            exit 255
+    esac
+    echo ${MD5}
+}
+
+mk_link_args() {
+    # Convert a dup_line of
+    # 'FILE dup1 dup2 ...'
+    # into format of
+    # 'FILE dup1'
+    # 'FILE dup2'
+    # '...'
+    # for use in link
+    echo "$@" | awk '{
+        for (i=2; i<=NF; i++) {
+            printf("%s %s\n", $1, $i);
+        }
+    }'
+}
+
+md5_link() {
+    # Link file if its md5 is equal to the original FILE.
+    # Args: 'FILE dup'
+    file="$1"
+    dup="$2"
+    file_path=`readlink -f "${file}"`
+    dup_path=`readlink -f "${dup}"`
+    if [ "${file_path}" = "${dup_path}" ]; then
+        err_msg "WARNING: '${file}' and '${dup}' are the same file"
+    else
+        md5_file=`md5 ${file}`
+        md5_dup=`md5 ${dup}`
+        if [ "${md5_file}" = "${md5_dup}" ]; then
+            #err_msg "rm -v \"${dup}\""
+            #err_msg "ln -sv \"${file}\" \"${dup}\""
+            rm -v "${dup}"
+            ln -sv "${file}" "${dup}"
+        else
+            err_msg "WARNING: '${file}' different to '${dup}'"
+        fi
+    fi
+}
+
+
+if [ $# -ne 1 ]; then
+    usage `basename $0`
+    exit 1
+fi
+
+dup_list="$1"
+cat "${dup_list}" | while read line; do
+    err_msg "${line}"
+    mk_link_args "${line}" | while read lk; do
+        err_msg " => " ${lk}
+        md5_link ${lk}
+    done
+done
+