printf padding with alternate character?

[pb]

Im wanted to pad out blank spaces with a specific character instead of
spaces or zeros, does C support that?

printf("$%*d", '*', 5); // Not sure what the format string is supposed to
look like to do this

example output i would want is this:
$********5

[Ben Pfaff]

Re: printf padding with alternate character?

"pb" <glace99@yahoo. com> writes:
[color=blue]
> Im wanted to pad out blank spaces with a specific character instead of
> spaces or zeros, does C support that?[/color]

No. You will have to write your own code to do it.
--
Ben Pfaff
email: blp@cs.stanford .edu
web: http://benpfaff.org

[Chris Torek]

Re: printf padding with alternate character?

In article <1103068973.180 47@sj-nntpcache-3> pb <glace99@yahoo. com> wrote:[color=blue]
>Im wanted to pad out blank spaces with a specific character instead of
>spaces or zeros, does C support that?[/color]

No.
[color=blue]
>printf("$%*d ", '*', 5); // Not sure what the format string is supposed to
>look like to do this[/color]

(Note that //-comments wrap around, so that if this had been intended
to be a code example, it would not have worked so well.

The "*" in "%*d" is a field-width specifier that reads an "int"
argument from the argument list, so:

printf("%*d", 2, 5);

prints the value "5" in a ten-character field. The field is blank
or zero padded depending on the pad option selected: blank by
default, zero if you use a 0 modifier.)
[color=blue]
>example output i would want is this:
>$********5[/color]

There is no standard way to do this. It is easy to build your own
though: just sprintf() the numeric value, and then work with the
string. In this case, to get an integer printed into a ten digit
field and replace leading blanks or zeros with spaces, just do
something like:

char buf[SOME_SIZE]; /* must be at least 11 chars */
int val;
...
sprintf(buf, "%010d", val); /* produces, e.g., 0000000005 */
subst(buf, '0', '*');

where the subst() function reads:

/*
* Do substitutions on leading characters in the given string:
* Replace all occurrences of "from" with "to". (We assume
* from != '\0'.)
*/
void subst(char *s, char from, char to) {
while (*s == from)
*s++ = to;
}

Note that if you print with leading blanks, you will need to subst()
from ' ' instead of '0'. (This trick works either way.)
--
In-Real-Life: Chris Torek, Wind River Systems
Salt Lake City, UT, USA (40°39.22'N, 111°50.29'W) +1 801 277 2603
email: forget about it http://web.torek.net/torek/index.html
Reading email is like searching for food in the garbage, thanks to spammers.

[Peter Nilsson]

Re: printf padding with alternate character?

pb wrote:[color=blue]
> Im wanted to pad out blank spaces with a specific character instead[/color]
of[color=blue]
> spaces or zeros, does C support that?[/color]

Yes, but not directly through a standard function.
[color=blue]
> printf("$%*d", '*', 5); // Not sure what the format string is[/color]
supposed to[color=blue]
> look like to do this
>
> example output i would want is this:
> $********5[/color]

#include <stdio.h>
#include <string.h>

#define HASH "*********"

int main(void)
{
int amount = 520;
char number[100];
sprintf(number, "%d.%02d", amount / 100, amount % 100);
printf( "$%.*s%s\n" ,
(int) (sizeof HASH - 1 - strlen(number)) ,
HASH,
number );
return 0;
}

BTW, $ is not a member of the basic character set.

--
Peter

[Mike Wahler]

Re: printf padding with alternate character?


"pb" <glace99@yahoo. com> wrote in message
news:1103068973 .18047@sj-nntpcache-3...[color=blue]
> Im wanted to pad out blank spaces with a specific character instead of
> spaces or zeros, does C support that?
>
> printf("$%*d", '*', 5); // Not sure what the format string is supposed to
> look like to do this
>
> example output i would want is this:
> $********5[/color]

You've got many good answers already. Here's another
alternative:

#include <iostream>
#include <string>
#include <stdio.h>

unsigned int digits(int value, unsigned int radix)
{
unsigned int result = 0;

if(value < 0)
value *= -1;

result = !value;

while(value)
{
++result;
value /= radix;
}

return result;
}

int main()
{
int value = 42;
int wid = 5;
char prefix = '$';
int leading = 0;
char pad = '*';
int i = 0;
unsigned int d = digits(value, 10) + (value < 0);

if(d > wid)
wid = d;

leading = wid - d ;

putchar(prefix) ;

for(i = 0; i < leading; ++i)
putchar(pad);

printf("%d\n", value);
return 0;
}

-Mike

[Martin Ambuhl]

Re: printf padding with alternate character?

Mike Wahler wrote:
[color=blue]
> You've got many good answers already. Here's another
> alternative:
>
> #include <iostream>
> #include <string>
> #include <stdio.h>[/color]

Did you forget this was comp.lang.c? It's a good thing, since you might
have gotten flamed in comp.lang.c++ for <stdio.h> instead of <cstdio>,
or, in their anti-C exuberance, for using either.

[Mike Wahler]

Re: printf padding with alternate character?


"Martin Ambuhl" <mambuhl@earthl ink.net> wrote in message
news:329tqnF3l8 pb9U1@individua l.net...[color=blue]
> Mike Wahler wrote:
>[color=green]
> > You've got many good answers already. Here's another
> > alternative:
> >
> > #include <iostream>
> > #include <string>
> > #include <stdio.h>[/color]
>
> Did you forget this was comp.lang.c?[/color]

Actually, no. Those C++ headers are 'residue' from
a 'scratch' file I forgot to delete. (I suppose they
must have been scrolled off the screen.)
[color=blue]
> It's a good thing, since you might
> have gotten flamed in comp.lang.c++ for <stdio.h> instead of <cstdio>,[/color]

Any flames about that would be unjustified. <stdio.h>
is as valid a standard header in C++ as in C. But yes,
I know, some folks don't know any better.
[color=blue]
> or, in their anti-C exuberance, for using either.[/color]

Let's not go there. :-)

But thanks for pointing out my error.
I'll try to pay better attention in the future.

-Mike

[Lawrence Kirby]

Re: printf padding with alternate character?

On Wed, 15 Dec 2004 00:37:38 +0000, Chris Torek wrote:

....
[color=blue]
> printf("%*d", 2, 5);
>
> prints the value "5" in a ten-character field.[/color]

Looks like a 2 character field to me. :-)
[color=blue]
> The field is blank
> or zero padded depending on the pad option selected: blank by
> default, zero if you use a 0 modifier.)
>[color=green]
>>example output i would want is this:
>>$********5[/color]
>
> There is no standard way to do this. It is easy to build your own
> though: just sprintf() the numeric value, and then work with the
> string. In this case, to get an integer printed into a ten digit
> field and replace leading blanks or zeros with spaces, just do
> something like:
>
> char buf[SOME_SIZE]; /* must be at least 11 chars */
> int val;
> ...
> sprintf(buf, "%010d", val); /* produces, e.g., 0000000005 */
> subst(buf, '0', '*');
>
> where the subst() function reads:
>
> /*
> * Do substitutions on leading characters in the given string:
> * Replace all occurrences of "from" with "to". (We assume
> * from != '\0'.)
> */
> void subst(char *s, char from, char to) {
> while (*s == from)
> *s++ = to;
> }
>
> Note that if you print with leading blanks, you will need to subst()
> from ' ' instead of '0'. (This trick works either way.)[/color]

That depends on whether you want 0 to be output as ********** or
*********0

Lawrence

[Zoran Cutura]

Re: printf padding with alternate character?

Chris Torek <nospam@torek.n et> wrote:[color=blue]
> In article <1103068973.180 47@sj-nntpcache-3> pb <glace99@yahoo. com> wrote:[/color]
....[color=blue]
> printf("%*d", 2, 5);[/color]
^^^
10???[color=blue]
>
> prints the value "5" in a ten-character field. The field is blank[/color]
^^^
two???
--
Z (zoran.cutura@w eb.de)
"LISP is worth learning for the profound enlightenment experience
you will have when you finally get it; that experience will make you
a better programmer for the rest of your days." -- Eric S. Raymond

[Chris Torek]

Re: printf padding with alternate character?

>On Wed, 15 Dec 2004 00:37:38 +0000, Chris Torek wrote:[color=blue][color=green]
>> printf("%*d", 2, 5);
>> prints the value "5" in a ten-character field.[/color][/color]

In article <pan.2004.12.15 .10.23.16.95300 0@netactive.co. uk>
Lawrence Kirby <lknews@netacti ve.co.uk> wrote:[color=blue]
>Looks like a 2 character field to me. :-)[/color]

Oops. Hasty posting....
[color=blue][color=green]
>> Note that if you print with leading blanks, you will need to subst()
>> from ' ' instead of '0'. (This trick works either way.)[/color]
>
>That depends on whether you want 0 to be output as ********** or
>*********0[/color]

Right, something else I managed to forget to bring up. And if this
is intended for printing money-amounts, one may have to fiddle with
negative numbers as more special cases.
--
In-Real-Life: Chris Torek, Wind River Systems
Salt Lake City, UT, USA (40°39.22'N, 111°50.29'W) +1 801 277 2603
email: forget about it http://web.torek.net/torek/index.html
Reading email is like searching for food in the garbage, thanks to spammers.

[Mike Wahler]

Re: printf padding with alternate character?

"Chris Torek" <nospam@torek.n et> wrote in message
news:cpq1g502ge @news1.newsguy. com...[color=blue][color=green]
> >On Wed, 15 Dec 2004 00:37:38 +0000, Chris Torek wrote:[color=darkred]
> >> printf("%*d", 2, 5);
> >> prints the value "5" in a ten-character field.[/color][/color]
>
> In article <pan.2004.12.15 .10.23.16.95300 0@netactive.co. uk>
> Lawrence Kirby <lknews@netacti ve.co.uk> wrote:[color=green]
> >Looks like a 2 character field to me. :-)[/color]
>
> Oops. Hasty posting....[/color]

I noticed it too, but realized it was merely a typo.
I didn't want to 'pick on' someone whose contributions
here I so highly value. :-)
[color=blue][color=green][color=darkred]
> >> Note that if you print with leading blanks, you will need to subst()
> >> from ' ' instead of '0'. (This trick works either way.)[/color]
> >
> >That depends on whether you want 0 to be output as ********** or
> >*********0[/color]
>
> Right, something else I managed to forget to bring up. And if this
> is intended for printing money-amounts, one may have to fiddle with
> negative numbers as more special cases.[/color]

While I did not test exhaustively, the example I posted allows
for the '-' character for negative values.

-Mike

[Chris Torek]

Re: printf padding with alternate character?

>"Chris Torek" <nospam@torek.n et> wrote in message[color=blue]
>news:cpq1g502g e@news1.newsguy .com...[color=green]
>> ... And if this
>> is intended for printing money-amounts, one may have to fiddle with
>> negative numbers as more special cases.[/color][/color]

In article <zk0wd.283$9j5. 18@newsread3.ne ws.pas.earthlin k.net>
Mike Wahler <mkwahler@mkwah ler.net> wrote:[color=blue]
>While I did not test exhaustively, the example I posted allows
>for the '-' character for negative values.[/color]

Well, yes; but I was referring to accountants' desire to print
negative numbers in parentheses, or with the minus sign at the
end, or with a "CR" (credit) or "DB" (debit) suffix, e.g.:

Your Bill

item 1 $***123.45
item 2 $****27.72 CR
total $****95.73

(I always thought these were obnoxious, myself. But my early
training was all mathematics rather than accounting. :-) )
--
In-Real-Life: Chris Torek, Wind River Systems
Salt Lake City, UT, USA (40°39.22'N, 111°50.29'W) +1 801 277 2603
email: forget about it http://web.torek.net/torek/index.html
Reading email is like searching for food in the garbage, thanks to spammers.

[Mike Wahler]

Re: printf padding with alternate character?


"Chris Torek" <nospam@torek.n et> wrote in message
news:cpq4r601r6 7@news4.newsguy .com...[color=blue][color=green]
> >"Chris Torek" <nospam@torek.n et> wrote in message
> >news:cpq1g502g e@news1.newsguy .com...[color=darkred]
> >> ... And if this
> >> is intended for printing money-amounts, one may have to fiddle with
> >> negative numbers as more special cases.[/color][/color]
>
> In article <zk0wd.283$9j5. 18@newsread3.ne ws.pas.earthlin k.net>
> Mike Wahler <mkwahler@mkwah ler.net> wrote:[color=green]
> >While I did not test exhaustively, the example I posted allows
> >for the '-' character for negative values.[/color]
>
> Well, yes; but I was referring to accountants' desire to print
> negative numbers in parentheses, or with the minus sign at the
> end, or with a "CR" (credit) or "DB" (debit) suffix, e.g.:
>
> Your Bill
>
> item 1 $***123.45
> item 2 $****27.72 CR
> total $****95.73[/color]

Oh, OK.
[color=blue]
>
> (I always thought these were obnoxious, myself. But my early
> training was all mathematics rather than accounting. :-) )[/color]

Well, I'm in the opposite 'camp'. All my early programming
learning was in the context of business applications (my first
HLL was COBOL :-) ), and yes, I had to deal with the forms
(value), valueCR, and value- as well. Since OP didn't give
context, I 'defaulted' to the 'simpler' -value. I suppose
the leading asterisks should have been a clue, though. :-)

Aside: One of the accounting oriented things I've done which
I found fun was converting a number to English (e.g. 3125 to
"Three thousand, one hundred twenty-five") for printing bank
drafts. :-)

I do wish I'd learned more math, though. (I struggle with other
than very simple graphics). I'm doing what I can to rectify that
problem when I have time.

Anyway, I'd like to take this opportunity to personally thank
you for all your valuable contributions here. I feel I'm
better with C because of you (and others here). :-)

-Mike

[lawrence.jones@ugs.com]

Re: printf padding with alternate character?

Chris Torek <nospam@torek.n et> wrote:[color=blue]
>
> Well, yes; but I was referring to accountants' desire to print
> negative numbers in parentheses, or with the minus sign at the
> end, or with a "CR" (credit) or "DB" (debit) suffix, e.g.:[/color]

Or, even more obnoxiously, simply printing them in red, a practice which
thankfully went out of fashion when monochrome copiers became prevalent.

-Larry Jones

I've got an idea for a sit-com called "Father Knows Zilch." -- Calvin