Programming Forums > Application Development > C

brad sue · Mar 14th, 2006, 6:46 PM

Hi , I am stuck with two dimension array of characters.

for example, I have 4 lines in a file( lines should be treated as arrays of string) called source:

i am not good at C.
i hope improve soon.
i need help.
it is very cold.

I want read the first two lines and store them in a 2-dimension array of characters called destination.

I know how to read (all the lines but not the first two) but when I tried to input the line in destination I get errors: I tried strcpy, memcpy...

What can I do please?
B

(Toggle Plain Text)

while( !feof(fin) ) {/* while begins*/
           count=0;
           for(i=0;i<5;i++)
           {fgets(source,sizeof(source),fin);
           strcpy(destination,source);
             count++
      /*if(count%2==0)*/
      fputs(hand,fout);

does not give what I want!!

DaWei · Mar 14th, 2006, 7:02 PM

What's wrong with using your count? Just count to two, don't look for the remainder unless you have some other objective.

Be very careful using eof as a loop exit at the top of the loop. Behavior can vary depending upon whether or not the last line in the file ends with a newline. Either way you decide to go can screw up performance if the other condition occurs. You'll wind up losing the last line or using it twice. I recommend making a "while (1)" loop and exiting explicitly when you detect EOF or error. Refer to your 'fgets' documentation very carefully.

nnxion · Mar 15th, 2006, 3:19 AM

Like DaWei said, just count to two. Here's what you can do.
[php]#include <stdio.h>
#include <string.h>

uhOh(char * error)
{
fprintf(stderr, "%s\n", error);
return 1;
}

main()
{
FILE * fin;
int i, count = 2;
char source[256];
char destination[2][256];

if((fin = fopen("source.txt", "rb")) == NULL)
{
return uhOh("Cannot open file");
}

for(i = 0; i < count; i++)
{
if(fgets(source, 100, fin) == NULL)
{
if(ferror(fin))
return uhOh("An error has occured, check it with ferror()");
if(feof(fin))
{
printf("done\n");
return 0;
}
}
else
{
strcpy(destination[i],source);
printf("LINE: %s\n", destination[i]);
}
}
fclose(fin);
}[/php]

You don't get to printing "done" because the for loop ends, but try filling in count = 5 instead.

DaWei · Mar 15th, 2006, 7:03 AM

ROFL, Ruben! You KNOW that I have the uhOh function and close relatives copyrighted!!!111!!eleven!

nnxion · Mar 15th, 2006, 9:01 AM

Quote:

Originally Posted by DaWei

ROFL, Ruben! You KNOW that I have the uhOh function and close relatives copyrighted!!!111!!eleven!

Haha, I always see you using it, so I thought I'd learn from the pro's.

@brad sue: The uhOh function with courtesy of DaWei.

InfoGeek · Mar 15th, 2006, 9:18 AM

[php]
return uhOh("An error has occured, check it with ferror()");[/php]
should be:
[php]
return uhOh("Trouble in River City.");
[/php]

brad sue · Mar 15th, 2006, 9:30 AM

Quote:

Originally Posted by InfoGeek

[php]
return uhOh("An error has occured, check it with ferror()");[/php]
should be:
[php]
return uhOh("Trouble in River City.");
[/php]

Infogeek,
Thank you very much
I am writing a standard C code, not php, but I think the logic is the same..
I will try it now.
Thank you
B

DaWei · Mar 15th, 2006, 9:36 AM

The 'PHP' tags don't necessarily indicate PHP code, bradsue, they cause syntax highlighting to occur whereas the ordinary 'code' tags don't. InfoGeek is teasing me because I often name the string in the function prototype as he has shown

.

brad sue · Mar 15th, 2006, 9:40 AM

OOHH!
I am sorry ( I know so littlle!!)

B.

Mar 14th, 2006, 6:46 PM	#1
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 115 Rep Power: 3	2 dimension array of characters Hi , I am stuck with two dimension array of characters. for example, I have 4 lines in a file( lines should be treated as arrays of string) called source: i am not good at C. i hope improve soon. i need help. it is very cold. I want read the first two lines and store them in a 2-dimension array of characters called destination. I know how to read (all the lines but not the first two) but when I tried to input the line in destination I get errors: I tried strcpy, memcpy... What can I do please? B (Toggle Plain Text) while( !feof(fin) ) {/* while begins/ count=0; for(i=0;i<5;i++) {fgets(source,sizeof(source),fin); strcpy(destination,source); count++ /if(count%2==0)/ fputs(hand,fout); while( !feof(fin) ) {/ while begins/ count=0; for(i=0;i<5;i++) {fgets(source,sizeof(source),fin); strcpy(destination,source); count++ /if(count%2==0)*/ fputs(hand,fout); does not give what I want!!

Mar 14th, 2006, 7:02 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	What's wrong with using your count? Just count to two, don't look for the remainder unless you have some other objective. Be very careful using eof as a loop exit at the top of the loop. Behavior can vary depending upon whether or not the last line in the file ends with a newline. Either way you decide to go can screw up performance if the other condition occurs. You'll wind up losing the last line or using it twice. I recommend making a "while (1)" loop and exiting explicitly when you detect EOF or error. Refer to your 'fgets' documentation very carefully. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Mar 15th, 2006, 3:19 AM	#3
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	Like DaWei said, just count to two. Here's what you can do. [php]#include <stdio.h> #include <string.h> uhOh(char * error) { fprintf(stderr, "%s\n", error); return 1; } main() { FILE * fin; int i, count = 2; char source[256]; char destination[2][256]; if((fin = fopen("source.txt", "rb")) == NULL) { return uhOh("Cannot open file"); } for(i = 0; i < count; i++) { if(fgets(source, 100, fin) == NULL) { if(ferror(fin)) return uhOh("An error has occured, check it with ferror()"); if(feof(fin)) { printf("done\n"); return 0; } } else { strcpy(destination[i],source); printf("LINE: %s\n", destination[i]); } } fclose(fin); }[/php] You don't get to printing "done" because the for loop ends, but try filling in count = 5 instead. __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Mar 15th, 2006, 7:03 AM	#4
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	ROFL, Ruben! You KNOW that I have the uhOh function and close relatives copyrighted!!!111!!eleven! __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Mar 15th, 2006, 9:18 AM	#6
InfoGeek Professional Programmer Join Date: Jun 2005 Location: India, The great. Posts: 435 Rep Power: 4	[php] return uhOh("An error has occured, check it with ferror()");[/php] should be: [php] return uhOh("Trouble in River City."); [/php] __________________ PFO - My daily dose of technology.

Mar 15th, 2006, 9:36 AM	#8
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	The 'PHP' tags don't necessarily indicate PHP code, bradsue, they cause syntax highlighting to occur whereas the ordinary 'code' tags don't. InfoGeek is teasing me because I often name the string in the function prototype as he has shown . __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Mar 15th, 2006, 9:40 AM	#9
brad sue Hobbyist Programmer Join Date: Mar 2006 Posts: 115 Rep Power: 3	OOHH! I am sorry ( I know so littlle!!) B.

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Programming Forums > Application Development > C

2 dimension array of characters