Incorrect help for --vmstat (confusion between -s/--swap and -y/--sys)

[F-S-T]

Hi,

SUMMARY

I think there is an error in help of --vmstat:
"-v, --vmstat equals -pmgdsc -D total"
It should say "-pmgdyc -D total s"

ISSUE TYPE

• Documentation Report

DOOL VERSION

Dool 1.3.0

OS / ENVIRONMENT

Red Hat 8 but not relevant.

STEPS TO REPRODUCE

dool -v 1 1
┄┄┄procs┄┄┄┬┄┄┄┄┄┄memory┄usage┄┄┄┄┄┬┄┄┄paging┄┄┬┄dsk/total┄┬┄┄┄system┄┄┬┄┄total┄cpu┄usage┄┄
run blk new│ used  free  cach  avai│  in   out │ read  writ│ int   csw │usr sys idl wai stl
  0   0 0.6│ 193M 1425M  321M 1613M│   0     0 │ 884k  358k│ 133   207 │  3   1  96   0   0

dool -pmgdsc -D total 1 1
┄┄┄procs┄┄┄┬┄┄┄┄┄┄memory┄usage┄┄┄┄┄┬┄┄┄paging┄┄┬┄dsk/total┄┬┄┄┄┄swap┄┄┄┬┄┄total┄cpu┄usage┄┄
run blk new│ used  free  cach  avai│  in   out │ read  writ│ used  free│usr sys idl wai stl
  0   0 0.6│ 193M 1425M  321M 1613M│   0     0 │ 883k  357k│   0  2048M│  3   1  96   0   0

dool -pmgdyc -D total 1 1
┄┄┄procs┄┄┄┬┄┄┄┄┄┄memory┄usage┄┄┄┄┄┬┄┄┄paging┄┄┬┄dsk/total┄┬┄┄┄system┄┄┬┄┄total┄cpu┄usage┄┄
run blk new│ used  free  cach  avai│  in   out │ read  writ│ int   csw │usr sys idl wai stl
  0   0 0.6│ 193M 1425M  321M 1613M│   0     0 │ 881k  356k│ 134   207 │  3   1  96   0   0

EXPECTED RESULTS

According to help, dool -v 1 1 should have same output than dool -pmgdsc -D total 1 1 (with swap columns)

ACTUAL RESULTS

dool -v 1 1 have same output than dool -pmgdyc -D total 1 1 (with sys columns).

Those results are conformed with source code (https://github.com/scottchiefbaker/dool/blob/master/dool#L176) which includes sys and not swap for vmstat:

            elif opt in ['-v', '--vmstat']:
                self.plugins += [ 'proc', 'mem', 'page', 'disk', 'sys', 'cpu' ]