C / C++ / MFC

Re: How to read from a text file?

9-Jan-06 2:18

Amarelia wrote:
I use fread() functions to read file in which it terminates when it gets some character even if there are still more data in file

fread() reads a specified number of bytes, and doesn't look at the characters at all:

// read 100 bytes
FILE *fp = fopen(filename, "rb");
BYTE buf[100];
int read = fread(buf, 1, 100, fp);
fclose(fp);

if you want to read the whole file, just keep calling fread(..) until it returns 0 (no bytes read).

Cleek | Image Toolkits | Thumbnail maker

toxcct9-Jan-06 2:21

toxcct

9-Jan-06 2:21

i think you problem may come from you write in a buffer not large enough.

do this :
1. get the number of characters in the file to be exctracted.
2. allocate your buffer with that number of bytes.
3. read() the totality of the file ; it will never overflow the buffer (considering the memory is correctly allocated)

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

Re: How to read from a text file?

David Crow9-Jan-06 3:06

David Crow

9-Jan-06 3:06

Amarelia wrote:
...it terminates when it gets some character...

Is it encountering an EOF character? If so, you need to open the file as binary, not text.

"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb

Printer Monitoring

micutzu9-Jan-06 1:44

micutzu

9-Jan-06 1:44

Hello,

Can anyone send me a link to a c++ sample that is able to track all pages sent to a local or network printer from a machine (running Windows XP)?

Thank you,

Regards,

Dan.

David Crow9-Jan-06 3:09

David Crow

9-Jan-06 3:09

Start here.

"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb

Try Empower Your Printing with Custom Print Processors

Dudi Avramov9-Jan-06 4:07

Dudi Avramov

9-Jan-06 4:07

David Crow9-Jan-06 4:18

David Crow

9-Jan-06 4:18

I think micutzu would benefit more from this suggestion.

"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb

\0 esc-characters in 4-byte-characters

micutzu10-Jan-06 1:55

micutzu

10-Jan-06 1:55

Thank you very much for your comments. I will read both articles and I hope it will help me.

Best Regards,

micutzu.

create window

Anu_Bala9-Jan-06 1:04

Anu_Bala

9-Jan-06 1:04

In MDI,I want a child window with some text from Main window menu list and also from tool bar?

Re: create window

toxcct9-Jan-06 2:06

toxcct

9-Jan-06 2:06

really needed to re-ask ?? Unsure | :~

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

bytefactory9-Jan-06 0:54

9-Jan-06 0:54

i run in a very strange c++ compiler problem.

until now i used the definition 'id' which gave me the right value ( = 0x00006964 ).
because i compile under window, mac and linux and the mac gcc compiler complains about wrong 4-byte-characters i added '\0\0id' to the definition which should give in my opinion the same result. but the vc++ and intel c++ compiler generates other values.

'id' = 0x00006964
'\0\0id' = 0x64690000

' id' = 0x20206964
'\40\40id' = 0x64692020

the most interesting things are the last 2 lines. what is the difference between a space written as space or as a esc-character? ... why does the compiler generates swapped values?

that doesn't makes sense to me ... any hints would be great ...

thanks
tilo

C^hris L^osinger9-Jan-06 1:34

9-Jan-06 1:34

google "Intel Byte Order"

Cleek | Image Toolkits | Thumbnail maker

bytefactory9-Jan-06 1:37

9-Jan-06 1:37

it's not the byteorder why i'm surprised. i'm confused because the 3rd line gives another byteorder than the 4th line with the same compiler and machine ...

tilo

C^hris L^osinger9-Jan-06 1:43

9-Jan-06 1:43

what code are you using to do the assignment ?

Cleek | Image Toolkits | Thumbnail maker

bytefactory9-Jan-06 1:51

9-Jan-06 1:51

e.g.

#define ANY_ID_1 'id' // gives the warning under gcc mac
#define ANY_ID_2 ' id' // gives the same byteorder like 'id'
#define ANY_ID_3 '\0\0id' // has the wrong byteorder

i use the defines as longs ...

cheers
tilo

C^hris L^osinger9-Jan-06 2:15

9-Jan-06 2:15

the compiler is probably treating '\40\40id' as a numeric literal (which causes the machine's byte-order rules for numerics to get involved).

it probably sees ' id' as a string literal (even though you shouldn't put multiple characters inside single quotes), and ends up doing something like:

char *p = " id";
long f = *(long*)p;

Cleek | Image Toolkits | Thumbnail maker

bytefactory9-Jan-06 2:50

9-Jan-06 2:50

hmmm ... strange things happens ...

i tried this one here ...

char *p = "\0\0id";
long f = *(long*)p;

if running this code f results in 0x64690000 ... that's exactly the same what the compiler generates with the constant '\0\0id' .. and that's swapped compared to 'id' which results in 0x00006964 ?!?!?!?!

this is one of the days where i don't understand compilers Smile | :)

... i want that the compiler generates the same constant when i write 'id' and '\0\0id' because this is obviously the same (for me!)

cheers
tilo

C^hris L^osinger9-Jan-06 3:00

9-Jan-06 3:00

bytefactory wrote:
i want that the compiler generates the same constant when i write 'id' and '\0\0id' because this is obviously the same (for me!)

bytefactory9-Jan-06 3:23

9-Jan-06 3:23

that would work but make a lot of work at another place in the program because i use the includefiles are parsed with an own scripting language that understands only 'xxxx' and numbers Smile | :)

thanks for the suggestion ...
tilo