Thread: scanf and formating data

>>You may want to try something like this to have the compiler do the math.
>Yes, that certainly takes away the math and simplifies things.



Yes, perhaps I should have said, "for maintenance issues -- if you ever adjust the size of an array, you only need to make one change." Or something like that. Poorly worded either way, I'll bet.

now my program is locked into an endless loop.
Does fscanf return EOF when the file has been completely read?
below is my updated code.

Dave_Sinkula

I attempted to modify your code, but it doesn't get past the second batch of data.

Code:

      char format[BUFSIZ];
      char label1[5],  label2[18], label3[14], label4[13], label5[18],
           label6[11], label7[12], label8[15], label9[7];
      sprintf(format, "%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,]"
              ",%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],%%*c",
              (int)(sizeof label1 - 1), (int)(sizeof label2 - 1),
              (int)(sizeof label3 - 1), (int)(sizeof label4 - 1),
              (int)(sizeof label5 - 1), (int)(sizeof label6 - 1),
              (int)(sizeof label7 - 1), (int)(sizeof label8 - 1),
              (int)(sizeof label9 - 1));
      printf("format = \"%s\"\n\n", format);

      while ( fscanf(file, format, label1, label2, label3, label4,
                     label5, label6, label7, label8, label9) == 9 )
      {
         /* ... */
      }

below is my modified version

Code:

         sprintf(buffer, "%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],"
                 "%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],%%%d[^,],",
                 (int)(sizeof(data[x].name)-1),(int)(sizeof(data[x].PeriTime)-1),
                 (int)(sizeof(data[x].PeriAU)-1),(int)(sizeof(data[x].Eccent)-1),
                 (int)(sizeof(data[x].LongPeri)-1),(int)(sizeof(data[x].LongNode)-1),
                 (int)(sizeof(data[x].Inclin)-1),(int)(sizeof(data[x].Semi)-1),
                 (int)(sizeof(data[x].Period)-1),(int)(sizeof(data[x].MPC)-1));

//line 58
         while(fscanf(infile,buffer,data[x].name,data[x].PeriTime,data[x].PeriAU,
                      data[x].Eccent,data[x].LongPeri,data[x].LongNode,data[x].Inclin,
                      data[x].Semi,data[x].Period,data[x].MPC)==10)
         {

            fscanf(infile,buffer,data[x].name,data[x].PeriTime,data[x].PeriAU,
                   data[x].Eccent,data[x].LongPeri,data[x].LongNode,data[x].Inclin,
                   data[x].Semi,data[x].Period,data[x].MPC);

            x++;
         }

what did i do wrong?
below is my output.

Name
Perihelion time
Perihelion AU
Eccentricity
Long. perihelion
Long. node
Inclination
Semimajor axis
Period

2P/Encke
2003-12-29.878

I think you may want to use "%%%d[^\n]%%*c" for the last element, since the lines don't end with commas. Also, check your PMs.

I noticed when trying to find what is wrong the while loop never tests true.

Code:

         while(fscanf(infile,buffer,
                      data[x].name,
                      data[x].PeriTime,
                      data[x].PeriAU,
                      data[x].Eccent,
                      data[x].LongPeri,
                      data[x].LongNode,
                      data[x].Inclin,
                      data[x].Semi,
                      data[x].Period,
                      data[x].MPC)==10)

Does it not like an array of structures?

It was the size of my arrays.
Apparantly fscanf() will not register a succesful read if it is placed into an incorrectly sized array.
Dave_Sinkula
you rock.
Thanks for all the help.
Check out your reputation.
how ever you do that

I spoke to soon on thinking the program was completed.
I have two lines of data I'm testing a reading.
The two differ from each other.

P/1996 R2 (Lagerkvist),2004-6-7.4051,2.622945,0.308525,334.2622,40.2251,2.6022,3 .79326,7.39 years, MPC 42666
C/1997 BA6 (Spacewatch),1999-11-28.0414,3.428902,0.998982,285.8451,317.6646,72.758 8,,, MPC 45960

I have my program written to accept the first line of the two, but not the second.
I attempted to change to fscanf() format to accept the tripple comma in the second line, but with no luck.

Sorry I do not speak french.
I unfortunately am restricted on the project of what I can use.
fstream.h is not allowed for this project.
I know of many easier ways, using C++, but that is restricted for this project also.

----------------below is weak free french translation.------------------

Désolé je ne parle pas le français. Je suis malheureusement limité sur le projet de ce que je peux utiliser. Le fstream.h n'est pas tenu le compte de ce projet. Je sais de beaucoup de façons plus faciles, le C d'utilisation + +, mais cela est limité pour ce projet aussi.

I'm sure that is not correct. Sorry.