| #!/bin/sh | |
| # This script uses the p utility to monitor all the interfaces for any | |
| # link level change. Any change that occurs will trigger an echo to | |
| # stdout or to the file received as argument, if there is any. | |
| if [ $# -gt 1 ]; then | |
| echo "Usage: $("basename $0") [output_filename]" | |
| exit 1 | |
| fi | |
| ip -oneline monitor link | | |
| while read line; do | |
| if [ $# = 1 ]; then | |
| echo >"$1" | |
| else | |
| echo "link monitor triggered" | |
| fi | |
| done |