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Home > Archive > Unix Shell > November 2005 > character count in ksh
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| Author |
character count in ksh
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| Dutchie 2005-11-09, 5:53 pm |
| I've made a ksh script to sent SMS messages from an AIX server. Now i
want to build in a
counter that counts down from 160 when i start typing the actual sms
text.
Does anybody has any suggestions?
Regards,
Arjan
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| Janis Papanagnou 2005-11-09, 5:53 pm |
| Dutchie wrote:
> I've made a ksh script to sent SMS messages from an AIX server. Now i
> want to build in a
> counter that counts down from 160 when i start typing the actual sms
> text.
>
> Does anybody has any suggestions?
To read at most 200 characters newer ksh support...
read -n 200
or read in everything and determine the length before sending it
read v
# then test ${#v} against limit
Janis
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| Rodrick Brown 2005-11-09, 5:53 pm |
|
"Janis Papanagnou" <Janis_Papanagnou@hotmail.com> wrote in message
news:dkqes9$l8m$1@online.de...
> Dutchie wrote:
>
> To read at most 200 characters newer ksh support...
>
> read -n 200
>
> or read in everything and determine the length before sending it
>
> read v
> # then test ${#v} against limit
>
>
> Janis
Actually the easiest way of doing what you want is possibly using PERL or C
or anything that can select()/poll stdin to have it update in real time you
will need to use some kind of curses based library.
--
Rodrick R. Brown
Unix Systems Admin
http://www.rodrickbrown.com
rodrick.brown[@]gmail.com
When in 1986 Apple bought a Cray X-MP and announced that they would use it
to design the next Apple Macintosh, Seymour Cray replied, "This is very
interesting because I am using an Apple Macintosh to design the Cray-2
supercomputer."
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Janis Papanagnou wrote:
> Dutchie wrote:
> read -n 200
> or read in everything and determine the length before sending it
> read v
> # then test ${#v} against limit
Yes. This is a very good solution.
Rodrick Brown wrote:
> Actually the easiest way of doing what you want is
> possibly using PERL or C or anything that can
> select()/poll stdin to have it update in real time you
> will need to use some kind of curses based library.
You PERL guys!! Always using a microtome to open an envelope
when just ripping it with your teeth is sufficient!  An underused
feature of ksh88 and newer is reading and writing from
/dev/tcp/<ip#>/<port#> or /dev/udp/<ip#>/<port#> to do
network transfers. Already built into ksh! netcat(1) or telnet(1)
are not necessary (I've seen scripts that implement mail(1)
without using external network tools).
>From the ksh93 FAQ at kornshell.com, talking about non-buffered
read input parsing, which can be extended to undertand how to
dynamically determine character length:
How can a write a ksh script that responds directly to each
character so that you user just has to enter y, not y<return>?
There are two ways to do this. The easiest is to use:
read -n1 x
Alternatively, you could do:
function keytrap
{
.sh.edchar=${sh.edchar}$'\n'
}
trap keytrap KEYBD
and then
read x
To wit, I would try:
function keytrap
{
(( ${#.sh.edchar}>=159 )) && .sh.edchar=${sh.edchar}$'\n'
}
trap keytrap KEYBD
read x
The above is not tested.
Alternately, a third technique is simple truncation, again
with ksh93(1) builtin operators:
SMS_MSG=${SMS_MSG:0:160} # or ${SMS_MSG:0:159} if NL is appended
I understand that not everybody has ksh version 1993 or newer.
It is available free under license from kornshell.com and some
hosts have it already installed under dtksh(1).
=Brian
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| Rodrick Brown 2005-11-09, 5:53 pm |
| On 2005-11-08 19:17:28 -0500, "bsh" <brian_hiles@rocketmail.com> said:
>
> Janis Papanagnou wrote:
>
> Yes. This is a very good solution.
>
> Rodrick Brown wrote:
>
> You PERL guys!! Always using a microtome to open an envelope
> when just ripping it with your teeth is sufficient! An underused
> feature of ksh88 and newer is reading and writing from
> /dev/tcp/<ip#>/<port#> or /dev/udp/<ip#>/<port#> to do
> network transfers. Already built into ksh! netcat(1) or telnet(1)
> are not necessary (I've seen scripts that implement mail(1)
> without using external network tools).
>
> read input parsing, which can be extended to undertand how to
> dynamically determine character length:
>
> How can a write a ksh script that responds directly to each
> character so that you user just has to enter y, not y<return>?
>
> There are two ways to do this. The easiest is to use:
>
> read -n1 x
>
> Alternatively, you could do:
>
> function keytrap
> {
> .sh.edchar=${sh.edchar}$'\n'
> }
> trap keytrap KEYBD
>
> and then
>
> read x
>
> To wit, I would try:
>
> function keytrap
> {
> (( ${#.sh.edchar}>=159 )) && .sh.edchar=${sh.edchar}$'\n'
> }
> trap keytrap KEYBD
> read x
>
> The above is not tested.
>
> Alternately, a third technique is simple truncation, again
> with ksh93(1) builtin operators:
>
> SMS_MSG=${SMS_MSG:0:160} # or ${SMS_MSG:0:159} if NL is appended
>
> I understand that not everybody has ksh version 1993 or newer.
> It is available free under license from kornshell.com and some
> hosts have it already installed under dtksh(1).
>
> =Brian
perl just makes it so easy sometime I easily forget this is comp.unix.shells
--
Rodrick R. Brown
Senior IT Consultant
http://www.rodrickbrown.com
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| Rodrick Brown wrote:
> PERL just makes it so easy sometime I easily forget this is comp.unix.shells
I disagree with you that PERL makes it necessarily "easy" in the sense
of
the level of abstraction, but will readily agree with you that perl, in
the sense
that however sophisticated the syntax, it's at least almost always
possible!
This is perhaps the fundamental criterion of the quality of any
programming
language.
=Brian
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| Chris F.A. Johnson 2005-11-11, 2:54 am |
| On 2005-11-09, Rodrick Brown wrote:
>
> PERL just makes it so easy sometime I easily forget this is comp.unix.shells
But it's not; it's comp.unix.shell. There is a moribund group of
that name.
My few attempts at learning PERL quickly drove me back to a sane
language, the shell.
--
Chris F.A. Johnson, author | <http://cfaj.freeshell.org>
Shell Scripting Recipes: | My code in this post, if any,
A Problem-Solution Approach | is released under the
2005, Apress | GNU General Public Licence
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