Weird Issue

[ncf]

Ok, I've been tring to resolve this issue for some time now (~1 day
which is way longer than normal for me) to no avail.

I am reading a file into a list in memory, using a "%" delimited file
format (which allows for comments on lines beginning with "#"), and
some of the messages are not correctly copied.

I believe the problem may be somewhere around the strcpy() call, but am
not sure at all.

I hope somebody out there is able to help me, no matter how cruddy my
code may be. :\
-Wes

=============== ===== MessagesFile.c= =============== ====
#include <stdio.h>
#include <string.h>

#define BUFFLEN 1024

#define same(x,y) strcmp(x,y)==0

int num_messages = 0;
char messages[][BUFFLEN] = {};

char buffer[BUFFLEN];

void ProcessLine(cha r *s) {
printf("Process Line(\"%s\")\n" ,s);

if (!strlen(s)) { /* Empty line */
} else if (s[0]=='#') { /* Comments begin with '#' */
} else if (same(s,"%")) { /* '%' is a message divider */
if (!strlen(buffer )) {
return;
}
/* Add the message */
strcpy(messages[num_messages++], buffer);

/* Clear the buffer */
int i;
for (i=0; i<BUFFLEN; i++) {
buffer[i] = '\0';
}
} else { /* Else, message */
int true_len;
if (strlen(buffer) ) {
true_len = (int)snprintf(b uffer, sizeof(buffer), "%s\n%s", buffer,
s);
} else {
true_len = (int)snprintf(b uffer, sizeof(buffer), "%s", s);
}
if (true_len > BUFFLEN) {
printf("Message %d truncated from %d bytes to %d bytes.",
num_messages+1, true_len, BUFFLEN);
}
}
}

int main()
{
FILE *myfile;

if ((myfile = fopen("messages .txt","r"))==NU LL) {
printf("Sorry, but I failed to open the file for reading.");
return 1;
}

int pos = 0;
char c;
char line[BUFFLEN] = "";
while ( (c=fgetc(myfile )) != EOF) {
if (c=='\n' || c=='\r') {
ProcessLine(lin e);
for (pos=0; pos<BUFFLEN; pos++)
line[pos] = '\0';
pos = 0;
} else {
line[pos++] = c;
}
}
if (strlen(line)) {
ProcessLine(lin e); /* first we dump whatever remaining buffer we have
into the process function */
}
ProcessLine("%" ); /* Then, for goodness sake, we make sure that
whatever buffer remaining is processed. */

fclose(myfile);

printf("\n\n=== =====\nMessages Dump\n========\ n");
int i;
for (i=0; i<num_messages ; i++) {
printf("Message[%d]=%s\n", i, messages[i]);
}

printf("Last Char Val=%d/%c",EOF,EOF);

return(0);
}

=============== ===== messages.txt (my test file) =============== =====
# comment!!!
meow mix
%
hi?
%
woot!
%
meow
%
Next message consists of exactly 1023 characters (leaving 1 for the
ending \0 :P)
%
aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa abb
%
And this message is
a multi-line message.
Woot!
%
A simple message with no end delimiter

=============== ===== Output of ``gcc MessageFile.c -Wall -o MessageFile
&& time ./MessageFile && echo $? =============== =====
ProcessLine("# comment!!!")
ProcessLine("me ow mix")
ProcessLine("%" )
ProcessLine("hi ?")
ProcessLine("%" )
ProcessLine("wo ot!")
ProcessLine("%" )
ProcessLine("me ow")
ProcessLine("%" )
ProcessLine("Ne xt message consists of exactly 1023 characters (leaving
1 for the ending \0 :P)")
ProcessLine("%" )
ProcessLine("aa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaab b")
ProcessLine("%" )
ProcessLine("An d this message is")
ProcessLine("a multi-line message.")
ProcessLine("Wo ot!")
ProcessLine("%" )
ProcessLine("A simple message with no end delimiter")
ProcessLine("%" )
========
Messages Dump
========
Message[0]=meow mix
Message[1]=
Message[2]=woot!
Message[3]=meow
Message[4]=Next message consists of exactly 1023 characters (leaving 1
for the ending \0 :P)
Message[5]=aaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aabb
Message[6]=
Woot!
Message[7]=A simple message with no end delimiter
Last Char Val=-1/ÿ
real 0m0.004s
user 0m0.000s
sys 0m0.000s
0

[Old Wolf]

ncf wrote:

Also, anyway I define `char messages[][BUFFLEN]`, I am getting an issue
with the element I'm trying to drop in at [1]. Adding lines to the
beginning of the file only changes which element is located at that
index and, consequently, dropped.

The only way I have found to stop the dropped element problem at index
[1] is to define the variable as `char messages[100][BUFFLEN]` or such,
wherein the array isn't as flexible as it once was.

You seem to think that "char messages[][BUFFLEN]" is some sort of
automatically-resizing structure. It isn't. It is effectively the
same as:

char messages[1][BUFFLEN]

ie. an array with only one row. Even less flexible than an array
with 100 rows.

[ncf]

Mark & Old Wolf, thanks. Yea, coming from python, the idea that an
array is 100% fixed is sort of odd to hear at first. But ok, I guess it
makes sense now.

Mark, I believe you misread my post, but that's no prob as I now see
what I'm doing wrong. (In the section where you mentioned I couldn't
strcpy() onto [1], I had mentioned that I'm defining it as the string I
quoted from the source)

Either way, I'm slightly confused about the malloc/realloc thing, but
hopefully I can find some tutorial online somewhere.

Thanks for all yoru help
-Wes