1.txt

将文本文挡的标识分开

#include "stdio.h"
#include "ctype.h"

#define LEN sizeof(struct entry)

char Buffer[256];


int state = 0;

int lineno=1;

char token[128];
int index=0;

int flag=0;               /*0代表字符串，1代表数字，2代表运算符*/

char* keyword[]={"int","float","short","char","long","break","case","const",
            "switch","continue","default","do","while","double","else","enum",
            "extern","for","goto","if","register","return","signed","sizeof",
            "static","struct","typedef","union","unsigned","void","volatile",
            "auto"};

FILE *out;

struct entry *headOfEntry;

/*符号表用链表*/
struct entry
{
    int attr;               /*记号*/
    char *value;            /*记号值*/
    struct entry *next;     /*指向下一结点指针*/
};

/*初始化符号链表*/
void entryinit()
{
    headOfEntry=(struct entry *)malloc(LEN);
    headOfEntry->next=NULL;
}

/*查询符号链表*/
int LookupEntry(char *c)                          /*字符串c是否存在于符号链表项中*/
{
                                                     /*若存在则返回1*/
    struct entry *e;                                /*若不存在则返回0*/
    int boolean=0;
    e=headOfEntry->next;
    while(e!=NULL)
    {
        if(strcmp(e->value,c)==0)
        {
            boolean=1;
            printf("\nvalue is %s and c is %s\n",e->value,c);
            return boolean;
        }
        e=e->next;
    }
    return boolean;
}

/*向符号链表中加入结点*/
void addToEntry(int f,char *symbol)
{
    /*char *c;*/
    struct entry *p;
    struct entry *new;

    p = headOfEntry;
    new = (struct entry *)malloc(LEN);
    if(f==0)
        new->attr=0;
    else if(f==1)
        new->attr=1;
    new->value=strdup(symbol);
    new->next=NULL;

    while(p->next!=NULL)
    {
        p = p->next;
    }

    p->next = new;
}

/*初始化输出文件*/
void outFile(char *outfile)
{
  if((out=fopen(outfile,"w"))==NULL)
  {
    printf("\nCan not open output file!\n");
    exit(0);
  }
}

void output(int f)
{
    int i;
    char *rec;
    rec=token;

    if(f==0)
    {
        for(i=0;i<31;i++)
        {
            if(strcmp(keyword[i],rec)==0)
            {
                printf("Line %d : ",lineno);
                fprintf(out,"Line %d : ",lineno);
                printf("( IDN , %s )\n",rec);
                fprintf(out,"( IDN , %s )\n",rec);
                addToEntry(0,rec);
                rec="";
                return;
            }
        }
        printf("Line %d : ",lineno);
        fprintf(out,"Line %d : ",lineno);
        printf("( id , %s )\n",token);
        fprintf(out,"( id , %s )\n",token);
        addToEntry(1,rec);
        return;
    }
    else if(f==1)
    {
        printf("Line %d : ",lineno);
        fprintf(out,"Line %d : ",lineno);
        printf("( num , %s )\n",token);
        fprintf(out,"( num , %s )\n",token);
    }
    else if(f==2)
    {
        printf("Line %d : ",lineno);
        fprintf(out,"Line %d : ",lineno);
        printf("( op , %s )\n",token);
        fprintf(out,"( op , %s )\n",token);
    }
}

void analyse(char *infile)
{
    FILE *fp;
    char recieve;
    char ch='#';

    int forward = -1;

    int temp,temp1;

    int pointer=0;

    if((fp=fopen(infile,"r"))==NULL)
    {
        printf("\nCan not open output file!\n");
        exit(0);
    }


    do
    {
        recieve = fgetc(fp);
        Buffer[pointer] = recieve;
        pointer++;
        if(pointer==127)
        {
            Buffer[pointer] = EOF;
            break;
        }
    }while(recieve!=EOF);              /*初始装入第一部分*/

    while(1)
    {
        forward = forward + 1;

        if(Buffer[forward] == EOF)
        {
            if(forward==127)
            {
                /*重装第二部分*/
                pointer = 128;
                do
                {
                    recieve = fgetc(fp);
                    Buffer[pointer] = recieve;
                    pointer++;
                    if(pointer==255)
                    {
                        Buffer[pointer] = EOF;
                        break;
                    }
                }while(recieve!=EOF);

                forward = forward + 1;
            }
            else if(forward==255)
            {
                /*重装第一部分*/
                pointer = 0;
                do
                {
                    recieve = fgetc(fp);
                    Buffer[pointer] = recieve;
                    pointer++;
                    if(pointer==255)
                    {
                        Buffer[pointer] = EOF;
                        break;
                    }
                }while(recieve!=EOF);

                forward = 0;
            }
            else
            {
                /*终止词法分析*/
                break;
            }
        }

        switch(state)
        {
            case 0: ch = Buffer[forward];
                    if(ch==' '||ch=='\t')
                        state = 0;
                    else if(ch=='\n')
                    {
                        lineno++;
                        state = 0;
                    }
                    else if(isalpha(ch))
                    {
                        index=0;
                        token[index]=ch;
                        index++;
                        state=1;
                    }
                    else if(isdigit(ch))
                    {
                        index=0;
                        token[index]=ch;
                        index++;
                        state=2;
                    }
                    else if(ch=='#'||ch=='('||ch==')'||ch=='['||ch==']'||ch=='{'||ch=='}'||ch=='.'||ch=='\\'
                        ||ch==';'||ch=='\''||ch=='?'||ch=='"'||ch=='%'||ch==','||ch==':')
                    {
                        index=0;
                        token[index]=ch;
                        index++;
                        flag=2;
                        token[index]='\0';
                        index++;
                        output(flag);
                        state=0;
                    }
                    else if(ch=='/')
                    {
                        state=3;
                        index=0;
                        token[index]=ch;
                        index++;
                    }
                    else if(ch=='+'||ch=='-'||ch=='*'||ch=='>'||ch=='<'||ch=='='||ch=='!')
                    {
                        state=5;
                        index=0;
                        token[index]=ch;
                        index++;
                    }
                    else if(ch=='|')
                    {
                        state=11;
                        index=0;
                        token[index]=ch;
                        index++;
                    }
                    else if(ch=='&')
                    {
                        state=12;
                        index=0;
                        token[index]=ch;
                        index++;
                    }
                    else
                    {
                        printf("Unprocessed char is %c\n",ch);
                        fprintf(out,"Unmatched char is %c\n",ch);
                        state = 0;
                    }
             break;

             case 1: ch = Buffer[forward];
                     if(isalnum(ch))
                     {
                         token[index]=ch;
                         index++;
                         state = 1;
                     }
                     else
                     {
                         state = 0;
                         token[index]='\0';
                         index++;
                         flag=0;
                         output(0);
                         forward = forward - 1;
                     }
             break;
             case 2: ch = Buffer[forward];                               /*寻找常数*/
                     if(isdigit(ch))
                     {
                        token[index]=ch;
                        index++;
                        state=2;