词法分析程序

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

typedef struct node{

    char *string;

    struct node *next;

}NODE;

int main()

{

    int i;

    char *ch;

    char *delim=":;,+-*/=";

    char input[20];

    char Keywords[][10]={{"auto"},{"double"},{"int"},{"struct"},{"break"},{"else"},{"long"},{"switch"},{"case"},

    {"enum"},{"register"},{"typedef"},{"char"},{"extern"},{"return"},{"union"},{"const"},{"float"},{"short"},{"unsigned"},{"continue"},

    {"for"},{"signed"},{"void"},{"default"},{"goto"},{"sizeof"},{"volatile"},{"do"},{"if"},{"while"},{"static"},{"+"},{"-"},{"*"},{"/"},{":"},

    {":="},{"<"},{"<="},{"<>"},{">"},{">="},{"="},{":"},{"("},{")"},{"#"},{"{"},{"}"}};

    char number[]="0123456789";

    char biaowords[]="abcdefghijklmnopqrstuvwxyz";

    NODE *head=NULL;

    NODE *thekeywords=NULL;

    NODE *biaoshi=NULL;

    NODE *yunsuanfu=NULL;

    NODE *shuzi=NULL;

    NODE *jiefu=NULL;

    NODE *p=NULL;

    NODE *q=NULL;

    head=(NODE*)malloc(sizeof(NODE));

    head->next=NULL;

    thekeywords=(NODE*)malloc(sizeof(NODE));

    thekeywords->next=NULL;

    biaoshi=(NODE*)malloc(sizeof(NODE));

    biaoshi->next=NULL;

    yunsuanfu=(NODE*)malloc(sizeof(NODE));

    yunsuanfu->next=NULL;

    jiefu=(NODE*)malloc(sizeof(NODE));

    jiefu->next=NULL;

    shuzi=(NODE*)malloc(sizeof(NODE));

    shuzi->next=NULL;

    //scanf("%s",input);

    do

    {

        scanf("%s\n",input);

        i=0;

        while(input[i] !='\0')

        {

            //printf("char=%c\n",input[i]);

            if(input[i] == '+' || input[i] == '-' || input[i] == '*' || input[i] == '/' || input[i] == '=')

            {

                //printf("\nhello\n");

                p=(NODE*)malloc(sizeof(NODE));

                p->next=NULL;

                p->string=(char*)malloc(sizeof(char)*2);

                p->string[0]='\0';

                strncpy(p->string,&input[i],1);

                p->next=yunsuanfu->next;

                yunsuanfu->next=p;

            //    printf("yunsuanfu is %c\n",input[i]);

            }

            else if(ispunct(input[i]) && input[i] != '~')

            {

                //ch=(char*)malloc(sizeof(NODE));

                p=(NODE*)malloc(sizeof(NODE));

                p->next=NULL;

                p->string=(char*)malloc(sizeof(char)*2);

                p->string[0]='\0';

                strncpy(p->string,&input[i],1);

                p->next=jiefu->next;

                jiefu->next=p;

            }

            i++;

        }

        ch=strtok(input,delim);

        do

        {

            if(input[0] =='~')

                break;

            q=head;

            p=(NODE*)malloc(sizeof(NODE));

            p->next=NULL;

            p->string=(char*)malloc(sizeof(input));

            p->string[0]='\0';

            strcat(p->string,ch);

            while(q->next !=NULL)

                q=q->next;

            p->next=q->next;

            q->next=p;

        }while(ch=strtok(NULL,delim));        

    }while(input[0] !='~');

    i=0;

    p=head->next;

    printf("\nhead:");

    while(p !=NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    p=head->next;

    while(p !=NULL)

    {

        q=(NODE*)malloc(sizeof(NODE));

        q->next=NULL;

        if(strspn(p->string,number))

        {

            q->string=p->string;

            q->next=shuzi->next;

            shuzi->next=q;            

        }

        else

        {

            for(i=0;i<=49;i++)

            {

                if(strcmp(p->string,Keywords[i])==0)

                {

                    q->string=Keywords[i];

                    if(i>=0 && i<=31)

                    {

                        q->next=thekeywords->next;

                        thekeywords->next=q;

                    }

                    else if(i>=32 && i<=35)

                    {

                        q->next=yunsuanfu->next;

                        yunsuanfu->next=q;

                    }

 

                    break;

                }

            }

        }

        if(i>49)

        {

            if(strspn(p->string,biaowords))

            {

 

                    q->string=p->string;

                    q->next=biaoshi->next;

                    biaoshi->next=q;                    

            }

        }

        p=p->next;

    }

    printf("\nthekeywords:\n");

    p=thekeywords->next;

    while(p != NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    printf("\nyunsuanfu:\n");

    p=yunsuanfu->next;

    while(p != NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    printf("\nbiaoshi:\n");

    p=biaoshi->next;

    while(p != NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    printf("\njiefu:\n");

    p=jiefu->next;

    while(p != NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    printf("\nshuzi:\n");

    p=shuzi->next;

    while(p != NULL)

    {

        printf("%s\t",p->string);

        p=p->next;

    }

    return 0;

}

 

<字母>：S-〉A|AA

　　　　　A->{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,w,y,

　　　　　　　　A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,S,Y,Z}
<数字>：S->A|AA|A0|A.

　　　　　A->{1,2,3,4,5,6,7,8,9}
<整数常数> ：S->A|AA|A0

　　　　  　   A->{1,2,3,4,5,6,7,8,9}

<标识符>：S->A|A_|AB

　　　　　　A->{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,w,y,

　　　　　　　　A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,S,Y,Z}

　　　　　　B->{0,1,2,3,4,5,6,7,8,9}

<关键字>：S->{int,float,double,long,unsige,static,include,define,for,if,whlie,do,for,...}

<运算符>：S->{+,-,*,/,%}
<界符>； S->{; , ( , ) , , }