Chet Ramey wrote:
I'm sure there are efficiency improvements possible in the bash indexed
array implementation, but sequentially accessing a data structure
optimized for space and sparse arrays is never going to be as fast as
a read-process loop, and that difference becomes more and more
Matthew Woehlke wrote:
Chet Ramey wrote:
I'm sure there are efficiency improvements possible in the bash indexed
array implementation, but sequentially accessing a data structure
optimized for space and sparse arrays is never going to be as fast as
a read-process loop, and that difference
It seems that mapfile is OK for small numbers but for bigger numbers it
starts to compsume time.
I made a litle test:
rm Xyz; unset MAPFILE # clear
max= # set limit
time for i in $(seq 0 $max); do echo 'Xyz' Xyz; done
real0m0.490s
user0m0.304s
sys 0m0.124s
time mapfile Xyz
Lennart Schultz wrote:
It seems that mapfile is OK for small numbers but for bigger numbers it
starts to compsume time.
Not exactly. Your own timing tests show that mapfile itself is blindingly
fast. The time is consumed sequentially traversing the (very large) array.
Bash indexed arrays are
2009-03-26, 21:22(-04), Chet Ramey:
Chris F.A. Johnson wrote:
Chet, how about an option to mapfile that strips leading and/or
trailing spaces?
Another useful option would be to remove newlines.
I'm disinclined to add one, since it's easy enough to use the
${line##[ ]} and
On Thu, Mar 26, 2009 at 05:59:14PM -0400, Chris F.A. Johnson wrote:
Chet, how about an option to mapfile that strips leading and/or
trailing spaces?
Another useful option would be to remove newlines.
It already has the latter:
-tRemove a trailing newline from
Chris,
I agree with you to use the right tool at the right time, and mapfile seems
not to be the right tool for my problem, but I will just give you some facts
of my observations:
using a fast tool like egrep just to find a simple string in my datafile
gives the following times:
time egrep 'pro'
On Fri, 27 Mar 2009, Lennart Schultz wrote:
Chris,
I agree with you to use the right tool at the right time, and mapfile seems
not to be the right tool for my problem, but I will just give you some facts
of my observations:
using a fast tool like egrep just to find a simple string in my
Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: i686-pc-linux-gnu-gcc
Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='i686'
-DCONF_OSTYPE='linu
x-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' -DCONF_VENDOR='pc'
-DLOCALEDIR='/usr/
On Thu, Mar 26, 2009 at 08:53:50AM +0100, Lennart Schultz wrote:
I have a bash script which reads about 25 lines of xml code generating
...
mapfile file
for i in ${mapfi...@]}
do
line=$(echo $i) # strip leading blanks
case $line in
done
With this change the job now
Lennart Schultz wrote:
Bash Version: 4.0
Patch Level: 10
Release Status: release
Description:
I have a bash script which reads about 25 lines of xml code generating
about 850 files with information extracted from the xml file.
It uses the construct:
while read line
do
case
On Thu, 26 Mar 2009, Lennart Schultz wrote:
I have a bash script which reads about 25 lines of xml code generating
about 850 files with information extracted from the xml file.
It uses the construct:
while read line
do
case $line in
done file
and this takes a little less than 2
Chris F.A. Johnson wrote:
Chet, how about an option to mapfile that strips leading and/or
trailing spaces?
Another useful option would be to remove newlines.
I'm disinclined to add one, since it's easy enough to use the
${line##[ ]} and ${line%%[]} constructs to
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