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drManhattan 02-05-2011 08:02 AM
how to read help in cmd's
 
Hi

Is there some guideline how to read help in linux cmd's ?
I have the follwing example below :
Code:
$lsof -?
lsof 4.81
 latest revision: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/
 latest FAQ: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ
 latest man page: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/lsof_man
 usage: [-?abhlnNoOPRtUvVX] [+|-c c] [+|-d s] [+D D] [+|-f[gG]]
 [-F [f]] [-g [s]] [-i [i]] [+|-L [l]] [+m [m]] [+|-M] [-o [o]] [-p s]
[+|-r [t]] [-s [p:s]] [-S [t]] [-T [t]] [-u s] [+|-w] [-x [fl]] [--] [names]
Defaults in parentheses; comma-separated set (s) items; dash-separated ranges.
  -?|-h list help          -a AND selections (OR)    -b avoid kernel blocks
  -c c  cmd c ^c /c/[bix]  +c w  COMMAND width (9)   
  +d s  dir s files        -d s  select by FD set    +D D  dir D tree *SLOW?*
                          -i select IPv[46] files    -l list UID numbers
  -n no host names        -N select NFS files        -o list file offset
  -O avoid overhead *RISK  -P no port names          -R list paRent PID
  -s list file size        -t terse listing          -T disable TCP/TPI info
  -U select Unix socket    -v list version info      -V verbose search
  +|-w  Warnings (+)      -X skip TCP&UDP* files    -- end option scan
  +f|-f  +filesystem or -file names    +|-f[gG] flaGs
  -F [f] select fields; -F? for help 
  +|-L [l] list (+) suppress (-) link counts < l (0 = all; default = 0)
                                        +m [m] use|create mount supplement
  +|-M  portMap registration (-)      -o o  o 0t offset digits (8)
  -p s  exclude(^)|select PIDs        -S [t] t second stat timeout (15)
  -T qs TCP/TPI Q,St (s) info
  -g [s] exclude(^)|select and print process group IDs
  -i i  select by IPv[46] address: [46][proto][@host|addr][:svc_list|port_list]
  +|-r [t[m<fmt>]] repeat every t seconds (15);  + until no files, - forever.
      An optional suffix to t is m<fmt>; m must separate t from <fmt> and
      <fmt> is an strftime(3) format for the marker line.
  -s p:s  exclude(^)|select protocol (p = TCP|UDP) states by name(s).
  -u s  exclude(^)|select login|UID set s
  -x [fl] cross over +d|+D File systems or symbolic Links
  names  select named files or files on named file systems
Anyone can list all files; /dev warnings disabled; kernel ID check disabled.
thx for help.

acid_kewpie 02-05-2011 08:18 AM
No, there are no standards, not sure why you'd need them TBH. If you wnat more data, you've very clearly got three sources of information printed right there, and I'd say you should usually refer to manpages for a decent level of information as a --help is only intended to be a brief reminder, not a way to learn about a tool.. so.... "man lsof" will be your friend.

btw, at university I was in a band called the Manhattan Engineering Project. Exciting huh?

MS3FGX 02-05-2011 08:19 AM
I'm not sure I understand the question. The help output lists the switches and their brief descriptions. Are you looking for something more detailed?

drManhattan 02-05-2011 08:42 AM
Yes, pretty nice 'acid_kewpie' but my nick comes from "Watchmen" movie.
;)

I was asking rather about semantics of brief help.
For example :
Code:
[+|-c c]
Does above mean "+c" OR "-c" OR "c" ?
Code:
[+D D]
Does above mean "+D" OR "D" ?
Code:
[+|-f[gG]]
Does above mean "+fg" OR "+fG" OR "-fg" OR "-fG" ?

I generally would like to know how to read semantics of brief help.

thx for help.

acid_kewpie 02-05-2011 10:57 AM
That's why you should read the manpage... It's there for a reason.


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