Support for /proc/[pid]/fdinfo/[fd]

[pirxthepilot]

Hello,

Any plans to support reading the contents of /proc/[pid]/fdinfo/[fd]? If not, but you think it's a good idea, I can try and submit a PR for it.

Thanks!

[SuperQ]

Can you describe what you're looking to use this for? This library is mostly focused around metrics extractions. I'm asking because it seems like the cardinality of the fdinfo data is very high.

[pirxthepilot]

In my case I would like to keep track of the number of inotify watches. From the proc man page:

              For inotify file descriptors (see inotify(7)), we see (since
              Linux 3.8) the following fields:

                  pos: 0
                  flags:    00
                  mnt_id:   11
                  inotify wd:2 ino:7ef82a sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:2af87e00220ffd73
                  inotify wd:1 ino:192627 sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:27261900802dfd73

              Each of the lines beginning with "inotify" displays informa‐
              tion about one file or directory that is being monitored.  The
              fields in this line are as follows:

              wd     A watch descriptor number (in decimal).

              ino    The inode number of the target file (in hexadecimal).

              sdev   The ID of the device where the target file resides (in
                     hexadecimal).

              mask   The mask of events being monitored for the target file
                     (in hexadecimal).

[grobie]

@pirxthepilot I'd be happy to reasonable PR to add this functionality.

[pirxthepilot]

@grobie awesome, thank you! I'll work on it and try to submit a PR within the next week. Do you recommend adding the functionality in proc.go, or a new file altogether?

[pgier]

Fixed in #115