奇怪的问题 [英] Weird Issue

问题描述

好的，我一直想解决这个问题已经有一段时间了（〜1天

这比我的正常时间长）无济于事。


我正在将文件读入内存中的列表，使用％分隔文件

格式（允许对以＃开头的行进行注释）和

某些消息未正确复制。


我相信这个问题可能在strcpy（）调用的某个地方，但是

根本不确定。


我希望有人在那里能够帮助我，无论我的代码是多么肮脏。 ：\

-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（char * s）{

printf（" ProcessLine（\"％s \"）\ n"，s ）;


if（！strlen（s））{/ *空行* /

}否则if（s [0] ==''＃ ''）{/ *评论以''＃''开头* /

}否则if（same（s，"％"））{/ *''％''是一条消息divider * /

if（！strlen（buffer））{

return;

}

/ * Add消息* /

strcpy（消息[num_messages ++]，缓冲区）;


/ *清除缓冲区* /

int i;

for（i = 0; i < BUFFLEN; i ++）{

buffer [i] =''\ 0'';

}

} else {/ *否则，消息* /

int true_len;

if（strlen（buffer））{

true_len =（int）snprintf（buffer，sizeof （缓冲区），％s \ n％s，缓冲区，

s）;

} else {

true_len =（int ）snprintf（buffer，sizeof（buffer），"％s"，s）;

}

if（true_len> BUFFLEN）{

printf（"消息％d从％d字节截断到％d字节。"，

num_messages + 1，true_len，BUFFLEN）;

}

}

}


int main（）

{

FILE * myfile;


if（（myfile = fopen（" messages.txt"，" r"））== NULL）{

printf（抱歉，但我没有打开文件进行阅读。）;

返回1;

}


int pos = 0;

char c;

char line [BUFFLEN] ="" ;;

while（（c = fgetc（myfile））！= EOF）{

if（c ==''\ n''|| c ==''\ r''） {

ProcessLine（行）;

for（pos = 0; pos< BUFFLEN; pos ++）

line [pos] =''\\ \\ 0'';

pos = 0;

}否则{

line [pos ++] = c;

}

}

if（strlen（line））{

ProcessLine（line）; / *首先我们将剩余的剩余缓冲区转储到流程函数中* /

}

ProcessLine（"％"）; / *然后，为了善良，我们确保

处理剩余的缓冲区。 * /


fclose（myfile）;


printf（" \ n \ n ======== \\ \\ nMessages转储\ 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）;

}


==================== messagess.txt（我的测试文件）======== ============

＃comment !!!

meow mix

％

hi？

％

woot！

％

喵喵

％

下一条消息包含1023个字符（剩下1个用于

结尾\ 0：P）

％

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaabb

％

和这个消息是

A多行信息。

Woot！

％

一条没有结束分隔符的简单消息


====================输出``gcc MessageFile.c -Wall -o MessageFile

&&时间./MessageFile&&回声$？ ====================

ProcessLine（&＃; comment !!!"）

ProcessLine（ meow mix）

ProcessLine（"％"）

ProcessLine（" hi？"）

ProcessLine（" ;％"）

ProcessLine（" woot！"）

ProcessLine（"％"）

ProcessLine（" meow"）

ProcessLine（"％"）

ProcessLine（"下一条消息包含1023个字符（留下

1 for结束\0：P）"）

ProcessLine从（QUOT;％"）

ProcessLine从（QUOT; aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa AAAAAA aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabb"）

ProcessLine从（QUOT;％"）

ProcessLine从（QUOT;而该消息是"）

ProcessLine（多行消息。）

ProcessLine（Woot！）

ProcessLine（"％） "）

ProcessLine（一条没有结束分隔符的简单消息）

ProcessLine（"％& ;）

========

消息转储

========

消息[0] =喵混合

消息[1] =

消息[2] = woot！

消息[3] = meow

消息[4] =下一条消息正好包含1023个字符（留下1

作为结尾\0：P）

消息[5] = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa AA aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaabb

消息[6] =

活泉！

消息[7] = A简单的消息没有结束分隔符

Last Char Val = -1 /？

real 0m0.004s

用户0m0.000s

sys 0m0.000s

0

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(char *s) {
printf("ProcessLine(\"%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(buffer, sizeof(buffer), "%s\n%s", buffer,
s);
} else {
true_len = (int)snprintf(buffer, 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"))==NULL) {
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(line);
for (pos=0; pos<BUFFLEN; pos++)
line[pos] = ''\0'';
pos = 0;
} else {
line[pos++] = c;
}
}
if (strlen(line)) {
ProcessLine(line); /* 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)
%
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaabb
%
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("meow mix")
ProcessLine("%")
ProcessLine("hi?")
ProcessLine("%")
ProcessLine("woot!")
ProcessLine("%")
ProcessLine("meow")
ProcessLine("%")
ProcessLine("Next message consists of exactly 1023 characters (leaving
1 for the ending \0 :P)")
ProcessLine("%")
ProcessLine("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabb")
ProcessLine("%")
ProcessLine("And this message is")
ProcessLine("a multi-line message.")
ProcessLine("Woot!")
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]=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaabb
Message[6]=
Woot!
Message[7]=A simple message with no end delimiter
Last Char Val=-1/?
real 0m0.004s
user 0m0.000s
sys 0m0.000s
0

推荐答案

？ ====================

ProcessLine（&＃; comment !!!"）

ProcessLine（ meow mix）

ProcessLine（"％"）

ProcessLine（" hi？"）

ProcessLine（" ;％"）

ProcessLine（" woot！"）

ProcessLine（"％"）

ProcessLine（" meow"）

ProcessLine（"％"）

ProcessLine（"下一条消息包含1023个字符（留下

1 for结束\0：P）"）

ProcessLine从（QUOT;％"）

ProcessLine从（QUOT; aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa AAAAAA aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabb"）

ProcessLine从（QUOT;％"）

ProcessLine从（QUOT;而该消息是"）

ProcessLine（多行消息。）

ProcessLine（Woot！）

ProcessLine（"％） "）

ProcessLine（一条没有结束分隔符的简单消息）

ProcessLine（"％& ;）

========

消息转储

========

消息[0] =喵混合

消息[1] =

消息[2] = woot！

消息[3] = meow

消息[4] =下一条消息正好包含1023个字符（留下1

作为结尾\0：P）

消息[5] = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa AA aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaabb

消息[6] =

活泉！

消息[7] = A简单的消息没有结束分隔符

Last Char Val = -1 /？

real 0m0.004s

用户0m0.000s

sys 0m0.000s

0

? ====================
ProcessLine("# comment!!!")
ProcessLine("meow mix")
ProcessLine("%")
ProcessLine("hi?")
ProcessLine("%")
ProcessLine("woot!")
ProcessLine("%")
ProcessLine("meow")
ProcessLine("%")
ProcessLine("Next message consists of exactly 1023 characters (leaving
1 for the ending \0 :P)")
ProcessLine("%")
ProcessLine("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabb")
ProcessLine("%")
ProcessLine("And this message is")
ProcessLine("a multi-line message.")
ProcessLine("Woot!")
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]=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaabb
Message[6]=
Woot!
Message[7]=A simple message with no end delimiter
Last Char Val=-1/?
real 0m0.004s
user 0m0.000s
sys 0m0.000s
0

很抱歉，问题在于消息[1]和

消息[6]。

Sorry, for clearification, the trouble lines are Message[1] and
Message[6].

2005年9月23日17:08:00 -0700，" ncf" < no *************** @ gmail.com>

在comp.lang.c中写道：

On 23 Sep 2005 17:08:00 -0700, "ncf" <no***************@gmail.com>
wrote in comp.lang.c:

好的，我已经花了一段时间来解决这个问题（〜1天
这对我来说比平常更长）无济于事。

我正在读一个使用％将文件存入内存中的列表分隔文件
格式（允许对以＃开头的行进行注释），并且
某些消息未正确复制。

我相信问题可能出现在strcpy（）电话周围的某个地方，但是我根本不确定。

我希望那里的人能够帮助我，无论我的代码多么肮脏是。 ：\
-Wes


我没有花很多时间查看你的代码，但确实如此。
产生未定义的行为在几个地方。

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

#define BUFFLEN 1024

＃定义相同的（x，y）strcmp（x，y）== 0
int num_messages = 0;


您知道吗，因为文件范围对象具有静态存储空间，所以它们会自动归零，除非您提供

具体的初始化？ = 0是多余的。

char messages [] [BUFFLEN] = {};


上面的行不是初始化的合法定义。如果你将
改为''{'''改为''{0}''，那就是。它会将''messages''定义为一个BUFFLEN字符数组的

数组。由于非法的

初始化程序，我不知道你的b / b
编译器的非标准行为对此有什么影响，但我严重怀疑它有什么不同<来自：

char消息[1] [BUFFLEN];

char buffer [BUFFLEN];

void ProcessLine（char * s）{
printf（" ProcessLine（\"％s \"）\ n"，s）;

if（！） strlen（s））{/ *空行* /
}如果（s [0] ==''＃''）{/ *评论以'''''开头* /
} else if（same（s，％））{/ *''％''是一个消息分隔符* /
if（！strlen（buffer））{
return;
}
/ *添加消息* /
strcpy（messages [num_messages ++]，buffer）;


第二次调用此函数时，您正在写完

的消息。未定义的行为。

/ *清除缓冲区* /
int i;
for（i = 0; i< BUFFLEN; i ++）{
buffer [i] =''\ 0'';
}


memset（）在这里会更有意义。

} else {/ *否则，消息* /
int true_len;
if（strlen（buffer））{
true_len =（int）snprintf（buffer，sizeof（buffer），"％s \ n％ s"，buffer，
s）;


您传递''缓冲''作为目标和源字符串

到snprintf（），更多未定义的行为。

} else {
true_len =（int）snprintf（buffer，sizeof（buffer），"％s"，s）;
}
if（true_len> BUFFLEN）{
printf（"消息％d从％d字节截断到％d字节。，
num_messages + 1，true_len，BUFFLEN）;
}
} }

int main（）
{FILE * myfile;

if（（myfile = fopen（" messages.txt"，） ; r"））== NULL）{
printf（抱歉，但我无法打开文件进行阅读。;
返回1;
}

int pos = 0;
char c;
char line [BUFFLEN] ="" ;;


你将行定义为BUFFLEN字符数组，所有''\ 0''。

while（（c = fgetc（myfile））！ = EOF）{
if（c ==''\ n''|| c ==''\ r''）{
ProcessLine（line）;


如果输入文件中的一行太长，您将溢出''line''并且

会产生更多未定义的行为。但是让我们暂时忽略这种可能性

。


让我们说文件中的前三行是：


abc

abcdefg

123


第一次拨打''ProcessLine''时，你会传递它abc跟随BUFFLEN的
- 3''\ 0''字符。第二次，你将通过它

" abcdefg"然后是BUFFLEN - 7''\ 0''字符。事实上，只要

每条新线的长度或长度都比之前的那条长或长，但是不会太长时间来溢出阵列，你传递了你的想法你是

路过。


但是当你读到第三行时，你会用

指针来调用你的函数; 123defg"然后是BUFFLEN - 7''\ 0''字符。

for（pos = 0; pos< BUFFLEN; pos ++）
line [pos] =''\''' ;
pos = 0;
} else {
line [pos ++] = c;
}
}
if（strlen（line））{< ProcessLine（line）; / *首先我们将剩余的缓冲区转储到流程函数中* /
}
ProcessLine（"％"）; / *然后，为了善良，我们确保
处理剩余的缓冲区。 * /

fclose（myfile）;

printf（" \ n \ n ======== \ nMessages Dump \\\
== ====== \ 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）;

返回（0）;
}

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
I haven''t spent a lot of time looking at your code, but it does
produce undefined behavior in several places.
==================== MessagesFile.c ====================
#include <stdio.h>
#include <string.h>

#define BUFFLEN 1024

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

int num_messages = 0;
Do you know that since file scope objects have static storage
duration, they are automatically zero initialized unless you provide a
specific initializer? The ''= 0'' is superfluous.
char messages[][BUFFLEN] = {};
The line above is not a legal definition with initialization. If you
changed ''{]'' to ''{0}'', it would be. It would define ''messages'' as an
array of one array of BUFFLEN characters. I have no idea what your
compiler''s non-standard behavior does with this due to the illegal
initializer, but I seriously doubt that it is anything much different
from:

char messages[1][BUFFLEN];
char buffer[BUFFLEN];

void ProcessLine(char *s) {
printf("ProcessLine(\"%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);
The second time you call this function, you are writing past the end
of ''messages''. Undefined behavior.
/* Clear the buffer */
int i;
for (i=0; i<BUFFLEN; i++) {
buffer[i] = ''\0'';
}
memset() would make a lot more sense here.
} else { /* Else, message */
int true_len;
if (strlen(buffer)) {
true_len = (int)snprintf(buffer, sizeof(buffer), "%s\n%s", buffer,
s);
You are passing ''buffer'' as both the destination and a source string
to snprintf(), more undefined behavior.
} else {
true_len = (int)snprintf(buffer, 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"))==NULL) {
printf("Sorry, but I failed to open the file for reading.");
return 1;
}

int pos = 0;
char c;
char line[BUFFLEN] = "";
You define line as an array of BUFFLEN characters, all ''\0''.
while ( (c=fgetc(myfile)) != EOF) {
if (c==''\n'' || c==''\r'') {
ProcessLine(line);
If a line in your input file is too long, you will overflow ''line'' and
produce more undefined behavior. But let''s ignore that possibility
for the moment.

Let''s say the first three lines in the file are:

abc
abcdefg
123

The first time you call ''ProcessLine'', you will pass it "abc" followed
by BUFFLEN - 3 ''\0'' characters. The second time, you will pass it
"abcdefg" followed by BUFFLEN - 7 ''\0'' characters. In fact as long as
each new line is as long or longer than the one before it, but not too
long to overflow the array, you are passing what you think you are
passing.

But when you read the third line, you will call your function with a
pointer to "123defg" followed by BUFFLEN - 7 ''\0'' characters.
for (pos=0; pos<BUFFLEN; pos++)
line[pos] = ''\0'';
pos = 0;
} else {
line[pos++] = c;
}
}
if (strlen(line)) {
ProcessLine(line); /* 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);
}

这里似乎有很多东西需要修复。也许

当你这么做时你的问题就会消失。


-

Jack Klein

主页： http://JK-Technology.Com

常见问题解答for

comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html

comp.lang.c ++ http://www.parashift.com/c++-faq-lite/

alt .comp.lang.learn.c-c ++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

There seem to be quite a few things here that need fixing. Perhaps
your problem will go away when you do.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.learn.c-c++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

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