То есть man-ы, ломая голову (с учётом моих знаний буржуйского), только я пытаюсь читать?
HISTCONTROL
A colon-separated list of values controlling how commands are
saved on the history list. If the list of values includes
ignorespace, lines which begin with a space character are not
saved in the history list. A value of ignoredups causes lines
matching the previous history entry to not be saved. A value of
ignoreboth is shorthand for ignorespace and ignoredups. A value
of erasedups causes all previous lines matching the current line
to be removed from the history list before that line is saved.
Any value not in the above list is ignored. If HISTCONTROL is
unset, or does not include a valid value, all lines read by the
shell parser are saved on the history list, subject to the value
of HISTIGNORE. The second and subsequent lines of a multi-line
compound command are not tested, and are added to the history
regardless of the value of HISTCONTROL.
HISTFILE
The name of the file in which command history is saved (see HIS‐
TORY below). The default value is ~/.bash_history. If unset,
the command history is not saved when an interactive shell
exits.
HISTFILESIZE
The maximum number of lines contained in the history file. When
this variable is assigned a value, the history file is trun‐
cated, if necessary, by removing the oldest entries, to contain
no more than that number of lines. The default value is 500.
The history file is also truncated to this size after writing it
when an interactive shell exits.
HISTIGNORE
A colon-separated list of patterns used to decide which command
lines should be saved on the history list. Each pattern is
anchored at the beginning of the line and must match the com‐
plete line (no implicit `*' is appended). Each pattern is
tested against the line after the checks specified by HISTCON‐
TROL are applied. In addition to the normal shell pattern
matching characters, `&' matches the previous history line. `&'
may be escaped using a backslash; the backslash is removed
before attempting a match. The second and subsequent lines of a
multi-line compound command are not tested, and are added to the
history regardless of the value of HISTIGNORE.
HISTSIZE
The number of commands to remember in the command history (see
HISTORY below). The default value is 500.
HISTTIMEFORMAT
If this variable is set and not null, its value is used as a
format string for strftime(3) to print the time stamp associated
with each history entry displayed by the history builtin. If
this variable is set, time stamps are written to the history
file so they may be preserved across shell sessions. This uses
the history comment character to distinguish timestamps from
other history lines.
Хошь длину укорачивай, хошь делай /dev/null файлом истории, хошь учись с пробелом секьюрные команды вводить (установив соответсвующую опцию),....
Как вариант
ln -s /dev/null ~/.bash_history
Но по мне так лучше учиться пробел ставить в командах, тогда и в bash_history будет что-то (опять не так притягивает внимание) и можно решать, что есть "плохо", а что "хорошо"