siva@bally.Bally.COM (Siva Chelliah) (01/21/91)
Hi,
I am running into problems when I mix floats and integers in sprintf.
1. How it is handled normally ? [Do not use "f" in sprintf ?
multiply by 10 and divide by 10 ?]
Thanks .
siva
main ()
{
char buf[90];
int i,j;
double k;
sprintf(buf,"%.4d%07.2f%.4d",45,445.34,1234);
printf("buf = %s\n",buf);
sscanf(buf,"%4d%7f%4d",&i,&k,&j);
printf("i = %d j = %d k= %7.2f",i,j,k);
}
------------ output of the above program ----------------
buf = 00450445.341234
i = 45 j = 1234 k= 8840025108807417000.00gceych@iago.caltech.edu (Eychaner, Glenn C.) (01/21/91)
siva@bally.Bally.COM (Siva Chelliah) writes... > I am running into problems when I mix floats and integers in sprintf. No. You are running into problems when you mix floats and doubles in scanf and sprintf. > double k; ^^^^^^^^ Note that k is declared as double. > sscanf(buf,"%4d%7f%4d",&i,&k,&j); ^^^ I believe this should be "%7lf", for a DOUBLE number. Same mistake is made in the next line of the program. > printf("i = %d j = %d k= %7.2f",i,j,k); ^^^^^ Sorry for posting this.....but it illustrates a BAD HABIT of confusing float with double (a habit I used to have). Glenn C. Eychaner | "Do you qualify to be alive, or is the limit of your senses 40386 N. Shore Ln `-----. so as only to survive?" -R.Stevens, _Mr.Businessman_ Big Bear City, CA 92314 `-----------------------. !**** G O N I N E R S ****! Eychaner%SunCub.Caltech.edu@Xhmeia.Caltech.edu -|- Big Bear Solar Observatory
gwyn@smoke.brl.mil (Doug Gwyn) (01/22/91)
In article <473@bally.Bally.COM> siva@bally.Bally.COM (Siva Chelliah) writes: > I am running into problems when I mix floats and integers in sprintf. No, sprintf() is doing what you intended. However, you made a mistake in your use of sscanf(); a %f format specifier must have a corresponding pointer-to-flaot argument, but you provided a pointer-to-double.
karl@ima.isc.com (Karl Heuer) (01/22/91)
In article <1991Jan21.004401.15257@nntp-server.caltech.edu> gceych@iago.caltech.edu writes: >> double k; >> sscanf(buf,"%4d%7f%4d",&i,&k,&j); > ^^^ >I believe this should be "%7lf", for a DOUBLE number. Right. This should fix the problem. >Same mistake is made in the next line of the program. >> printf("i = %d j = %d k= %7.2f",i,j,k); Wrong. For printf(), "%f" is correct and "%lf" is illegal. This unfortunate asymmetry is a result of history and the default widening rules. (You'll probably find that "%lf" works on your local implementation of printf(). But since "%f" also works and is Standard, that's the one to use. Fix it now, before you port to an implementation that works differently.) Karl W. Z. Heuer (karl@ima.isc.com or uunet!ima!karl), The Walking Lint
blair_wilson@canrem.uucp (blair wilson) (01/24/91)
SC>Hi,
SC> I am running into problems when I mix floats and integers in sprintf.
SC> 1. How it is handled normally ? [Do not use "f" in sprintf ?
SC> multiply by 10 and divide by 10 ?]
SC>main ()
SC>{
SC> char buf[90];
SC> int i,j;
SC> double k;
SC> sprintf(buf,"%.4d%07.2f%.4d",45,445.34,1234);
SC> printf("buf = %s\n",buf);
SC> sscanf(buf,"%4d%7f%4d",&i,&k,&j);
SC> printf("i = %d j = %d k= %7.2f",i,j,k);
SC>}
SC>------------ output of the above program ----------------
SC>buf = 00450445.341234
111122222223333
1111 field 1 - this looks correct, your specifier %.4d, asks
for a field MINIMUM 4 wide (I would think spaces would be used
as place holders, but this may be implementation defined)
2222222 field 2 - also correct. A float 7 wide with leading
0's and 2 decimal places (this time you asked for leading 0's
with the 0 in the format spec.
3333 field 3 - also correct. A four digit integer occupying 4
spaces
You may want to seperate your fields with a space to make them
easier to decode, i.e. "\n%.4d %07.2f %.4d" will force a
couple of spaces between each field.
SC>i = 45 j = 1234 k= 8840025108807417000.00
field k messes up in this case because you need to specify %lf
for doubles, so its stuffing a float, rather than a double, at
the address you specify.
Hope this helps
email - blair.wilson@canremote.uucp
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NorthAmeriNet HostRob.Doucette@f701.n250.z1.fidonet.org (Rob Doucette) (02/11/91)
>main () >{ > char buf[90]; > int i,j; > double k; > sprintf(buf,"%.4d%07.2f%.4d",45,445.34,1234); > printf("buf = %s\n",buf); > sscanf(buf,"%4d%7f%4d",&i,&k,&j); > printf("i = %d j = %d k= %7.2f",i,j,k); >} >------------ output of the above program ---------------- >buf = 00450445.341234 >i = 45 j = 1234 k= 8840025108807417000.00 >--- D'Bridge 1.30/001331 > * Origin: EGSGATE Fidonet<->Usenet Gateway (1:250/98) >(1:250/416) Try changing line 5 to read - float k; You could instead change line 6 to read sscanf(buf, "%4.d%07.3lf%.4d", 45, 445.34, 1234); L8R. -- EGSGate Fidonet Gateway, Toronto (egsgate.fidonet.org) ...!{uunet, moore, lsuc}!eastern!egsgate