[C++][Plasma] plasma_store should show usage

[asfimport]

Currently the options exposed by the plasma_store executable aren't very discoverable:

$ plasma_store -h
please specify socket for incoming connections with -s switch
Abandon
(pyarrow) antoine@fsol:~/arrow/cpp (ARROW-2135-nan-conversion-when-casting *)$ plasma_store 
please specify socket for incoming connections with -s switch
Abandon
(pyarrow) antoine@fsol:~/arrow/cpp (ARROW-2135-nan-conversion-when-casting *)$ plasma_store --help
plasma_store: invalid option -- '-'

Reporter: Antoine Pitrou / @pitrou
Assignee: Christian Hudon / @chrish42

Related issues:

• Plasma-store-server does not support --help, shows backtrace on getopt error (is duplicated by)

PRs and other links:

• GitHub Pull Request #7025

_{Note: This issue was originally created as ARROW-2260. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
@pcmoritz, @robertnishihara.

[asfimport]

Wes McKinney / @wesm:
Ran into this today. Pretty unfriendly

$ plasma_store -h
WARNING: Logging before InitGoogleLogging() is written to STDERR
F1001 14:09:55.488880 366765504 store.cc:1160] please specify socket for incoming connections with -s switch
*** Check failure stack trace: ***
*** Aborted at 1569956995 (unix time) try "date -d @1569956995" if you are using GNU date ***
PC: @                0x0 (unknown)
*** SIGABRT (@0x7fff785eb2c6) received by PID 3111 (TID 0x115dc65c0) stack trace: ***
    @     0x7fff7869bb5d _sigtramp
Abort trap: 6

[asfimport]

Christian Hudon / @chrish42:
Oups. Didn't check for duplicates before reporting ARROW-7585. I'm willing to do the work to fix this as a good first Arrow pull request. Antoine mentioned GFlags as the library to use (that would be more featureful than getopt()), so I'll use that unless someone says otherwise here... 

[asfimport]

Micah Kornfield / @emkornfield:
Issue resolved by pull request 7025
#7025