<s>
pexec	B-Application
is	O
a	O
command-line	B-Application
utility	O
for	O
Linux	B-Application
and	O
other	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
which	O
allows	O
the	O
user	O
to	O
execute	O
shell	B-Device
commands	B-Application
in	O
parallel	B-Operating_System
.	O
</s>
<s>
The	O
specified	O
code	O
can	O
be	O
executed	O
either	O
locally	O
or	O
on	O
remote	O
hosts	O
,	O
in	O
which	O
case	O
ssh	B-Protocol
is	O
used	O
to	O
build	O
a	O
secure	O
tunnel	O
between	O
them	O
.	O
</s>
<s>
Similar	O
to	O
shell	B-Device
loops	O
,	O
a	O
variable	O
is	O
changed	O
as	O
the	O
loop	O
starting	O
the	O
tasks	O
iterates	O
,	O
so	O
that	O
many	O
values	O
can	O
get	O
passed	O
to	O
the	O
specified	O
command	O
or	O
script	O
.	O
</s>
<s>
pexec	B-Application
is	O
a	O
free	B-Application
software	I-Application
utility	O
,	O
and	O
part	O
of	O
the	B-Application
GNU	I-Application
Project	I-Application
.	O
</s>
<s>
The	O
most	O
common	O
usage	O
is	O
to	O
replace	O
the	O
shell	B-Device
loop	O
,	O
for	O
example	O
:	O
</s>
<s>
taking	O
the	O
input	O
set	O
from	O
a	O
file	O
instead	O
of	O
command	B-Application
line	I-Application
argument	O
;	O
</s>
<s>
support	O
for	O
mutual	B-Operating_System
exclusions	I-Operating_System
and	O
atomic	O
command	O
executions	O
inside	O
the	O
shell	B-Device
loop	O
(	O
in	O
order	O
to	O
,	O
e.g.	O
</s>
<s>
avoid	O
unexpectedly	O
high	O
I/O	O
load	B-Operating_System
)	O
;	O
</s>
<s>
using	O
alternative	O
remote	B-Protocol
shells	I-Protocol
instead	O
of	O
ssh	B-Protocol
.	O
</s>
<s>
using	O
supervisor	O
daemons	O
to	O
balance	O
between	O
the	O
resources	O
of	O
concurrent	B-Operating_System
pexec	B-Application
instances	O
.	O
</s>
<s>
Such	O
optional	O
features	O
can	O
be	O
requested	O
using	O
command-line	B-Application
arguments	O
.	O
</s>
<s>
By	O
default	O
,	O
pexec	B-Application
tries	O
to	O
detect	O
the	O
number	O
of	O
CPUs	B-Device
and	O
uses	O
all	O
of	O
them	O
.	O
</s>
