Difference between revisions of "Port to PID"
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Use the `lsof` command to find which process is listening on a given port. | Use the `lsof` command to find which process is listening on a given port. | ||
− | For example, I saw that some process was already using port 69 (normally TFTP). I did not expect this port to be in use, so I ran the following command to find out which process what listening on port 69: | + | The -n option for `lsof` turns of reverse name resolution which speeds up the output. Otherwise it will try to reverse each IP address to a name. |
+ | |||
+ | For example, say I saw that some process was already using port 69 (normally TFTP). I did not expect this port to be in use, so I ran the following command to find out which process what listening on port 69: | ||
+ | |||
+ | <pre> | ||
+ | lsof -n -i :69 | ||
+ | </pre> | ||
+ | |||
+ | To find which process is listening on port 80 (you would expect some http server): | ||
<pre> | <pre> | ||
− | lsof -i : | + | lsof -n -i :80 |
</pre> | </pre> | ||
− | + | To see who is connected via SSH or SCP look for port 22: | |
<pre> | <pre> | ||
− | lsof -i : | + | lsof -n -i :22 |
</pre> | </pre> | ||
Line 18: | Line 26: | ||
<pre> | <pre> | ||
− | lsof -u USER | + | lsof -n -u USER |
</pre> | </pre> | ||
<pre> | <pre> | ||
− | lsof -c COMMAND | + | lsof -n -c COMMAND |
</pre> | </pre> |
Revision as of 14:50, 25 September 2008
Use the `lsof` command to find which process is listening on a given port.
The -n option for `lsof` turns of reverse name resolution which speeds up the output. Otherwise it will try to reverse each IP address to a name.
For example, say I saw that some process was already using port 69 (normally TFTP). I did not expect this port to be in use, so I ran the following command to find out which process what listening on port 69:
lsof -n -i :69
To find which process is listening on port 80 (you would expect some http server):
lsof -n -i :80
To see who is connected via SSH or SCP look for port 22:
lsof -n -i :22
You can also look for files opened by a given user or command:
lsof -n -u USER
lsof -n -c COMMAND