HW点是应该从文件中读取它：
int func(int arg) { int x = 7; char c = 'a'; arg = x + c; return arg; }
并输出：
func, arg, x, c
//or optionally also the next line
int, char, return
所以我的问题是在我的输出上出现应该出现的字符的问号，并且strcmp没有为我的if语句返回零，这要求它起作用（注意：我有很多评论和printf来帮助我弄清楚我哪里出错了）：
while((d=fgetc(function_file)) != EOF) {
//start by checking for any defines and just looping until a new line character comes up
if( d == '#')
flag = true;
if((d == '\n') && (flag)){
//flag which says if I am searching for a newline but only after a define/include
//was found will I say the flag is not needed anymore to allow normal parsing
flag = false;
} //end of check for a define function
if( (flag == false) && (d != '#') ) {
//this is where the main chunk of code goes to do all the parsing
if((d != ' ') && (d != '\t') && (d !='\n') && (d != '{') && (d != '}') && (d != '(') && (d != ')') && (d != '*') && (d != '=') && (d != '+')) {
printf("Character read is : %c\n", d);
start = true;
temp[count] = c;
count++;
}
}//end of main chunk of code
if((start == true) && ((d == ' ') || (d == '(') || (d == ')') || (d == '{') || (d == '}'))) {
//end a string and compare it hear
if(match == false) {
temp[count] = '\0';
printf("String: %s\n", temp);//*********************************DEBUGGING***********
start = false;
int compare;
for(compare = 0; compare < key_counter; compare++) {
int optimus;
optimus = strcmp(keywords[compare], temp); //************** ONE OF THE ERRORS IS HERE***************************************?
if(optimus == 0){
//printf("this is actually runnning");//*********************************DEBUGGING***********
int len = strlen(temp);
bizarro_keywords[bizarro_key_counter] = (char *)malloc(sizeof(char) * (len +1));
memcpy(bizarro_keywords[bizarro_key_counter], temp, len +1);
printf("\nWhats inside bizarro_key_counter right after it is allocated memory: %s", bizarro_keywords[bizarro_key_counter]);
bizarro_key_counter++;
match = true;
}
}
int x;
for(x = 0; x < count; x++)
temp[x] = '\0';
count = 0;
} else { //if match equals true just grab the next available string
//printf("is this one ever running?");
temp[count] = '\0';
start = false;
printf("String: %s\n", temp);
int len = strlen(temp);
identifiers[iden_counter] = (char *)malloc(sizeof(char) * (len +1));
memcpy(identifiers[iden_counter], temp, len +1);
iden_counter++;
match = false;
int x;
for(x = 0; x < count; x++)
temp[x] = '\0';
count = 0;
}
}
}//end of while loop for reading the whole file
这是我的输出：
Character read is : i
Character read is : n
Character read is : t
String: ???
Character read is : f
Character read is : u
Character read is : n
Character read is : c
String: ????
Character read is : i
Character read is : n
Character read is : t
String: ???
Character read is : a
Character read is : r
Character read is : g
String: ???
Character read is : i
Character read is : n
Character read is : t
String: ???
Character read is : x
String: ?
Character read is : 7
Character read is : ;
String: ??
Character read is : c
Character read is : h
Character read is : a
Character read is : r
String: ????
Character read is : c
String: ?
Character read is : '
Character read is : a
Character read is : '
Character read is : ;
String: ????
Character read is : a
Character read is : r
Character read is : g
String: ???
Character read is : x
String: ?
Character read is : c
Character read is : ;
String: ??
Character read is : r
Character read is : e
Character read is : t
Character read is : u
Character read is : r
Character read is : n
String: ??????
Character read is : a
Character read is : r
Character read is : g
Character read is : ;
String: ????
我是C的新手，我迷失了为什么我得到了那个输出。请提示。
答案 0 :(得分：1)
据我所知，你只想从输入文件中读取行并将其拆分为标记。您可以使用strtok函数而不是从文件中读取字符：
char* keywords[] = { "int", "char", "return" };
int i = 0, j, keywordsCount = 3;
FILE* f = fopen("a.txt", "r");
char line[1000], *token;
while (fgets(line, 1000, f) != NULL) // read line
{
char* token = strtok(line, " \t\n{}()*+=,;");
while (token != NULL)
{
printf("String %d:%s", i++, token);
for (j = 0; j < keywordsCount; ++j)
if (strcmp(token, keywords[j]) == 0)
{
printf(" <-- Look, it's keyword!");
break; // breaks for, not while
}
putchar('\n');
token = strtok(NULL, " \t\n{}()*+=,;");
}
}
请注意，我在分隔符字符串中使用'\n'字符，因为fgets函数会在最后包含'\n'的缓冲区中读取行。
文件内容a.txt：
int func(int arg) { int x = 7; char c = 'a'; arg = x + c; return arg; }
输出：
String 0:int <-- Look, it's keyword!
String 1:func
String 2:int <-- Look, it's keyword!
String 3:arg
String 4:int <-- Look, it's keyword!
String 5:x
String 6:7
String 7:char <-- Look, it's keyword!
String 8:c
String 9:'a'
String 10:arg
String 11:x
String 12:c
String 13:return <-- Look, it's keyword!
String 14:arg
答案 1 :(得分：0)
您的代码有点难以阅读 - 至少第四部分（尽管有评论）因为它太长了。
你应该将你的功能分成几个较小的功能，你甚至已经有了第1-4步的结构。现在，因为你重新使用之前声明的变量，当你进入第四步时可能会偷偷摸摸count而不是= = 0这样的问题。因为有太多的扭曲和转动它有点难以看到问题
当你进行这样的词法分析时，通常最好使用状态机，切换语句对此有用，例如
typedef enum { Idle, Include , ... } states_t;
states_t state=Idle;
switch (state)
{
case Idle:
switch ( d )
{
case '#':
state = Include;
break;
...
break;
case Include:
...
break;
break;
如果您没有调试器，请包含assert.h并在您的代码中放置断言以确保捕获所有假设，即assert( count == 0 );在第4步之前可能是件好事。
在复制时使用strcpy或更好strncpy而不是memcpy，strcpy - 系列在遇到\ 0更有效时会停止复制（它会复制\ 0以及。）