adding difflines

shell/difflines.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+#
+# SPDX-License-Identifier: MIT
+
+diff --unchanged-line-format="" \
+  --old-line-format="%dn: %L" \
+  --new-line-format="%dn: %L" \
+  "$1" "$2" | sort -n
+
+# This is handy for situations where you need a line-by-line
+# comparison of two similar outputs, such as ldd against two
+# different libraries to find out if one of them is different
+# (extra dependencies). For example:
+#
+# ldd libsomething.so.old | sort > old.txt
+# ldd libsomething.so.new | sort > new.txt
+#
+# diffl.sh old.txt new.txt
+# 1:  /usr/lib64/ld-linux-x86-64.so.2 (0x00007f61ba4c7000)
+# 1:  /usr/lib64/ld-linux-x86-64.so.2 (0x00007f6b96d6b000)
+# 2:  libc.so.6 => /usr/lib/libc.so.6 (0x00007f61b89f2000)
+# 2:  libc.so.6 => /usr/lib/libc.so.6 (0x00007f6b95092000)
+# 3:  libdl.so.2 => /usr/lib/libdl.so.2 (0x00007f61b8376000)
+# 3:  libdl.so.2 => /usr/lib/libdl.so.2 (0x00007f6b94a16000)
+# ...