Re: string to integer

[DennisW]

On Apr 2, 8:19 am, Javier Montoya <jmonto...@gmail.com> wrote:
> On Mar 19, 6:04 pm, DennisW <dennistwilliam...@gmail.com> wrote:
>
>
>
>
>
> > On Mar 19, 6:50 am, Javier Montoya <jmonto...@gmail.com> wrote:
>
> > > On Mar 19, 12:39 pm, Javier Montoya <jmonto...@gmail.com> wrote:
>
> > > > Dear all,
>
> > > > I have a several directories with *.jpg images. The image files are
> > > > named as ascending numbers and I would like to retrieve the lowest and
> > > > largest image number in each directory. An example of the content of a
> > > > directory is given below:
> > > > /bla/bla/bla/dir1
> > > > -> 00000.jpg
> > > > -> 00001.jpg
> > > > ->
> > > > -> 09001.jpg
>
> > > > The desired output would be the integer numbers: 0 and 9001
> > > > With the code below, I'm able to retrieve in "seqInterval" array,
> > > > which is the lowest and largest image number as strings.
> > > > seqDir="/bla/bla/bla/dir1"
> > > > seqInterval=($(find $seqDir -name "*.jpg" | sort | sed -n -e '1p;$p' |
> > > > sed -e 's|^.*/||' -e 's/\.[^.]*$//'))
> > > > in our example, I obtain sth. like:
> > > > seqInterval[0] is equal to "00000" and seqInterval[1] is equal to
> > > > "09001"
> > > > Since those are string numbers, I was wondering which is the best way
> > > > to convert those strings into integer numbers (seqInterval[0]=0 and
> > > > seqInterval[1]=9001)?
>
> > > > I tried the code below, but it doesn't work properly, any suggestions?
> > > > startImg=$(printf '%d' ${seqInterval[0]})
> > > > endImg=$((printf '%d' ${seqInterval[1]}))
>
> > > > Best whishes
>
> > > Dear all,
>
> > > I found a solution:
>
> > > startImg=$(printf '%d' ${seqInterval[0]//0/})
> > > endImg=$(printf '%d' ${seqInterval[1]//0/})
>
> > > Is there's a better way, pls let me know!
>
> > In the case of 09001 your command results in "91"
>
> > Try:
>
> > shopt -s extglob
> > printf '%d' ${seqInterval[0]/#*(0)/}
> > printf '%d' ${seqInterval[1]/#*(0)/}
>
> > which says "delete a sequence of zero or more '*()' zeros anchored at
> > the beginning '#' of the string"
>
> Thanks Dennis! But in the case of 000000, I obtain an empty value.
> Ideally, I should keep just one zero.
>
> Best wishes

$ shopt -s extglob
$ declare -a
seqInterval='([0]="000000" [1]="000001" [2]="009001" [3]="390001")'
$ for i in {0..3}; do printf '%d\n' ${seqInterval[i]/#*(0)/}; done
0
1
9001
390001

Tested in Bash versions 3.2.49(23)-release and 4.0.33(1)-release.