I feel it has been slightly faster in cygwin-1.7 than cygwin-1.6. But it
is still very slow compared to msys-1.10. What does cygwin indeed
execute when start up? Is it loaded too much, for example the network
libraries? I noticed that paths leading with two slashes '//', which is
often created by path join functions, for example $prefix/somewhere,
when $prefix points to the root "/". When such paths (//...) are
accessed, cygwin seems to treat it as some kind of URL and halt for
several seconds, while msys always merge the duplicated slashes to '/...'.
Because of the slow speed, when I'm programming with cygwin, I will
carefully to invoke command calls to the cygwin executables, to reduce
the start up cost. for example, if I want to uppercase a string, I will
do it in 26 built-in variable expansion as:
VAR="${VAR//a/A}"
VAR="${VAR//b/B}"
VAR="${VAR//c/C}"
...
VAR="${VAR//z/Z}"
rather then by simply execute:
VAR=$(echo $VAR | tr [a-z] [A-Z])
because, this execution will add 2 times of start-up delay, one for
`bash`, and other one for `tr`. When my script will uppercase 100 or
more words, that delay is unaffordable.
# toupper VAR
function toupper() {
local v=${!1}
v=${v//a/A}
v=${v//b/B}
v=${v//c/C}
v=${v//d/D}
v=${v//e/E}
v=${v//f/F}
v=${v//g/G}
v=${v//h/H}
v=${v//i/I}
v=${v//j/J}
v=${v//k/K}
v=${v//l/L}
v=${v//m/M}
v=${v//n/N}
v=${v//o/O}
v=${v//p/P}
v=${v//q/Q}
v=${v//r/R}
v=${v//s/S}
v=${v//t/T}
v=${v//u/U}
v=${v//v/V}
v=${v//w/W}
v=${v//x/X}
v=${v//y/Y}
v=${v//z/Z}
eval "$1=\"$v\""
}
bash-3.2$ time -p for ((i=1; i<100; i++)); do var=$(echo $i | tr [a-z]
[A-Z]); done
real 13.57
user 8.40
sys 6.90
bash-3.2$ time -p for ((i=1; i<100; i++)); do var=$i; toupper var; done
real 0.12
user 0.12
sys 0.00
If I try it on linux, though the first always slower, but it's a lot
faster then in cygwin.
This may be not a good example, what I mean is, I must consider the
start up cost in cygwin, I write scripts in bash, and using binutils
etc. to get the programs look more elegant and more precise, and more
portable, but If I consider too much start up cost, the result code must
be very dirty.
Any ideas?
Lenik
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