1 files changed, 41 insertions, 0 deletions

diff --git a/bin/unix/fdswap b/bin/unix/fdswap
new file mode 100755
index 0000000..251cdea
--- /dev/null
+++ b/bin/unix/fdswap
@@ -0,0 +1,41 @@
+#!/bin/bash
+#
+# fdswap
+# 
+# Orignal author: ingvarha
+# ref: https://ingvarha.wordpress.com/2010/07/10/changing-a-process-file-descriptor-on-the-fly/
+
+if [ "$2" = "" ]; then
+<<HELP cat
+Usage: ${0##*/} /path/to/oldfile /path/to/newfile [pids]
+Example: ${0##*/} /var/log/daemon.log /var/log/newvolume/daemon.log 1234
+Example: ${0##*/} /dev/pts/53 /dev/null 2345
+HELP
+  exit 0
+fi
+
+if ! gdb --version &>/dev/null; then
+  echo "Unable to find gdb."
+  exit 1
+fi
+
+src="$1"; dst="$2"; shift; shift 
+pids=$* 
+
+for pid in ${pids:=$( /sbin/fuser $src | cut -d ':' -f 2 )}; 
+do
+  echo "src=$src, dst=$dst"
+  echo "$src has $pid using it" 
+  cmd=$(mktemp)
+  { 
+    echo "attach $pid" 
+    echo 'call (int)open("'$dst'", 66, 0666)'
+    for ufd in $(LANG=C ls -l /proc/$pid/fd | \
+    grep "$src"\$ | awk ' { print $9; } '); 
+    do echo 'call (int)dup2($1,'"$ufd"')'; done 
+    echo 'call (int)close($1)'
+    echo 'detach'; echo 'quit' 
+    sleep 5
+  } | tee /dev/tty >$cmd
+  gdb -x $cmd
+done