reading double from dynamically unsigned char array

Question

I'm going to read data directly from a "gz" format file. Using "zlib" in c, I read the data from gz file and now I have an unsigned char array namely "str". I want to extract double numbers using "sscanf". here is my code:

printf("%s\n", str);
double d1,d2,d3;
sscanf(str, "%lf %lf %lf", &d1, &d2, &d3);
printf("%lf\n", &d1);
printf("%lf\n", &d2);
printf("%lf\n", &d3);

and the output is:

23.323 1111.232 434434.1
0.000000
0.000000
0.000000

it seems I have successfully read str from gz file, but I cannot read doubles from str.

trr with %1d instead of%1f

jasinth premkumar
– jasinth premkumar

2019-07-20 14:02:04 +00:00
Commented Jul 20, 2019 at 14:02 — jasinth premkumar
– jasinth premkumar, Commented Jul 20, 2019 at 14:02

RobertBaron · Accepted Answer · 2019-07-20 15:25:36Z

1

This will work. This is because %lf expect a double value and you were passing a pointer to a double value.

printf("%lf\n", d1);
printf("%lf\n", d2);
printf("%lf\n", d3);

edited Jul 20, 2019 at 15:25

answered Jul 20, 2019 at 14:11

RobertBaron

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1 Comment

Jonathan Leffler Over a year ago

I think you should explain the change.

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