How to use C language to realize simple employee information management system

How to use C Language implementation of a simple staff information management system

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The code implementation is as follows ：

#include <stdio.h>// Input 、 Output instruction #include <malloc.h>// Dynamic allocation in memory size Byte storage area #include <string.h>// String related operation instructions #include <stdlib.h>// Five types 、 Some macros and general utility functions #include<conio.h>// Corresponding operation generated by keyboard #include <MEMORY.H>// Store access header file typedef struct node{         char   name[20];     int    age;     int    worktime;     char   sex[20];     char   marrige[20];     int    grade;     char   tired[20];    struct  node *next;}STU;void output(STU *head);STU *Create();STU *findByName(STU *head,char *name);STU *findByWorktime(STU *head,int worktime);STU *findByGrade(STU *head,int grade);void find(STU *head);STU *insert(STU *head);STU *findByNumEx(STU *head,char num[],STU **ppbefore);STU *del(STU *head);void update(STU *head);void sort(STU *head);void save_info(STU *head);void copy();STU *load_info();char *password();void main(){          char *p;     int i,n=0;        char a[40];        printf("        \t\t******* Welcome to the employee information management system ********\n\n");          printf("        \t\t please input password :\n");        printf("        \t\t----------:\n");    for(i=0;i<3;i++)    {           n=n+1;        printf("        \t\t The first %d Time input :",i+1);        p=password();       if(p!=NULL)       {           STU *head;            int choice;            int n;            head=NULL;             printf("\n        \t\t You are a legal user !\n\n");        for (i = 0; i < 0x7FFFFFF; i++);        for (i = 0; i < 0x7FFFFFF; i++);        for (i = 0; i < 0x7FFFFFF; i++);        system("cls");        for(;;)            {                system("cls");                printf("           \t\t******* Employee information management system ********\n");                printf("           \t\t* 1. Enter employee information               *\n");                printf("           \t\t* 2. Display all employee information           *\n");                printf("           \t\t* 3. Query employee information               *\n");                printf("           \t\t* 4. New employee information               *\n");                printf("           \t\t* 5. Delete employee information               *\n");                printf("           \t\t* 6. Modify employee information               *\n");                printf("           \t\t* 7. Sort employee information             *\n");                printf("           \t\t* 8. Save the current information to a file         *\n");                printf("           \t\t* 9. Back up information to file         *\n");                printf("           \t\t* 10. Load employee information from file        *\n");                printf("           \t\t* 0. Exit the system                   *\n");                printf("           \t\t*******************************\n");                printf("           \t\t Please select (0-9):");                scanf("%d",&choice);                if(choice==0) break;                switch(choice)                {                       case 1: head=Create(); break;                    case 2: output(head);break;                    case 3:find(head);break;                    case 4: head=insert(head); break;                    case 5: head=del(head); break;                    case 6: update(head);break;                    case 7: sort(head);break;                    case 8: save_info(head);break;                    case 9: copy();break;                    case 10:head=load_info();break;                }            printf(" Press any key to continue ....");            getch();        }        printf("           \t\t Thank you for using , bye !\n");        break;        }       else       {            printf("\n        \t\t You are an illegal user !\n\n");           if(n==3)            printf("           \t\t Your wrong password times exceed 3 Time , Program closed !\n");       }    }}STU *Create(){    STU *head,*pnew,*pend;    head=NULL;    printf(" Enter employee information :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");    for(;;)     {        pnew=(STU *)malloc(sizeof(STU));        scanf("%s",pnew->name);        if(strcmp(pnew->name,"0")==0)        {            printf(" Employee information is entered \n");            break;        }        scanf("%d%d%s%s%d%s",&pnew->age,&pnew->worktime,pnew->sex,pnew->marrige,&pnew->grade,pnew->tired);        pnew->next=NULL;         if(head==NULL){            head=pnew;            pend=pnew;        }        else{            pend->next=pnew;            pend=pend->next;        }    }    return head;}void output(STU *head){    STU *p;    printf(" The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");    for(p=head;p!=NULL;p=p->next)        printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",p->name,p->age,p->worktime,p->sex,p->marrige,p->grade,p->tired);}void find(STU *head){    STU *p;    char name[20];    int worktime,grade,i;    int choice;    system("cls");for(;;)    {        system("cls");        printf("           \t\t******* Employee information inquiry system ********\n");        printf("           \t\t* 1. Search by employee name             *\n");        printf("           \t\t* 2. Search by length of service             *\n");        printf("           \t\t* 3. Search by employee level             *\n");        printf("           \t\t* 0. Exit the system                   *\n");        printf("           \t\t*******************************\n");        printf("           \t\t Please select (0-3):");        scanf("%d",&choice);        if(choice==0) break;        switch(choice)        {               case 1:                    printf(" Please enter the employee name :");                    scanf("%s",name);                    p=findByName(head,name);break;            case 2:                     printf(" Please enter the length of service :");                    scanf("%d",&worktime);                    p=findByWorktime(head,worktime);break;            case 3:                    printf(" Please enter employee level :");                    scanf("%d",&grade);                    p=findByGrade(head,grade);break;        }        if(p==NULL)    {            printf(" There is no information related to this employee !\a\n");    }    else    {         if(choice==1)         {                 printf(" The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");              for(p=head;p!=NULL;p=p->next)             {                if(strcmp(p->name,name)==0)                printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",p->name,p->age,p->worktime,p->sex,p->marrige,p->grade,p->tired);             }         }         else if(choice==2)         {                  printf(" The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");                for(p=head;p!=NULL;p=p->next)                 {                    if(p->worktime==worktime)                    printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",p->name,p->age,p->worktime,p->sex,p->marrige,p->grade,p->tired);                 }            }         else if(choice==3)         {                           printf(" The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");                    for(p=head;p!=NULL;p=p->next)                    {                        if(p->grade==grade)                        printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",p->name,p->age,p->worktime,p->sex,p->marrige,p->grade,p->tired);                    }        }    }    printf(" Press any key to continue ....");    getch();}printf("           \t\t You have exited the inquiry system \n\n");}STU *findByName(STU *head,char *name){    STU *p,*result=NULL;    for(p=head;p!=NULL;p=p->next)        if(strcmp(p->name,name)==0)        {            result=p;            break;        }return result;}STU *findByWorktime(STU *head,int worktime){    STU *p,*result=NULL;    for(p=head;p!=NULL;p=p->next)        if(p->worktime==worktime)        {            result=p;            break;        }return result;}STU *findByGrade(STU *head,int grade){    STU *p,*result=NULL;    for(p=head;p!=NULL;p=p->next)        if(p->grade==grade)        {            result=p;            break;        }        return result;}STU *insert(STU *head){    STU *pnew,*pcur,*pbefore,*p;    int choice;    printf(" Enter employee information :\n");    for(;;)    {        //1. Apply for a new node and assign a value         pnew=(STU *)malloc(sizeof(STU));        printf(" The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");        scanf("%s%d%d%s%s%d%s",pnew->name,&pnew->age,&pnew->worktime,pnew->sex,pnew->marrige,&pnew->grade,pnew->tired);        pnew->next=NULL;        //2. Insert the new node into the linked list         // If the list is empty , And just insert ; If the list is not empty , Then find the location , Then insert     if(head==NULL)    {        head=pnew;      }    else    {        pcur=NULL;        for(p=head;p!=NULL;pbefore=p,p=p->next)            if(strcmp(p->name,pnew->name)==1)            {                pcur=p;                break;            }            // After finding , Judge pcur Is it empty ,            // if pcur It's empty , be pnew The node should be inserted at the end of the linked list          if(pcur==NULL)        {            pbefore->next=pnew;         }        // if pcur Non empty , be pnew The node should be inserted into pcur Before ,pbefore after , here , There are two more cases ：        //pcur It points to the first node , perhaps pcur Point to subsequent nodes ;        else        {            if(pcur==head)            {                pnew->next=pcur;                head=pnew;            }            else            {                pnew->next=pcur;                pbefore->next=pnew;            }        }    }    printf(" Please select : Press 1 Continue to add -> Press 0 End adding \n");    printf("choice=");    scanf("%d",&choice);    if(choice==0)        {               printf(" Information added !\n");            break;        }    }   return head;}STU *del(STU *head){    STU *presult,*pbefore;    char name[20];    printf(" Employee information to be deleted :");    scanf("%s",&name);    presult=findByNumEx(head,name,&pbefore);    if(presult!=NULL)    {        printf(" eureka ! The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");          printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",presult->name,presult->age,presult->worktime,presult->sex,presult->marrige,presult->grade,presult->tired);            if(presult==head)        {            head=presult->next;        }        else        {            pbefore->next=presult->next;        }        printf(" Delete successful ---> ");    }    else        printf(" There is no information related to this employee \a\a\n");    return head;}// Function description ：//   stay head In the linked list pointed to , Look up the student ID as num The node of //   After finding , Returns two values ： Pointer to the current node presult, Pointer to the previous node of the current node pbefore,//  presult Return by function return value ( namely return),pbefore Through output type parameters ppBefore return STU *findByNumEx(STU *head,char name[],STU **ppbefore){    STU *p,*presult=NULL,*pbefore=NULL;    for(p=head;p!=NULL;pbefore=p,p=p->next)        if(strcmp(p->name,name)==0)        {            presult=p;            break;        }    if(p==NULL)    pbefore=NULL;    *ppbefore=pbefore;    return presult;}void update(STU *head){    STU *presult;    char name[20];    printf(" Enter the name of the employee to be modified :\n");    scanf("%s",name);    presult=findByName(head,name);    if(presult==NULL)        printf(" Check no one ! Can't modify !\a\n");    else    {    printf(" eureka ! The employee information is as follows :\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");      printf("%s\t%d\t%d\t%s\t%s\t%d\t%s\n",presult->name,presult->age,presult->worktime,presult->sex,presult->marrige,presult->grade,presult->tired);            printf(" Please enter modification information :\n");        printf(" full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");               scanf("%s%d%d%s%s%d%s",presult->name,&presult->age,&presult->worktime,presult->sex,presult->marrige,&presult->grade,presult->tired);        printf(" The modification is complete ---> ");    }}void sort(STU *head)// Sort by level {    STU *pi,*pj,*pindex,*p;    STU temp;    int len=sizeof(STU)-sizeof(STU *);    int i,j,n=0;    for(p=head;p!=NULL;p=p->next)        n++;    for(pi=head,i=0;i<n-1;i++,pi=pi->next){        pindex=pi;        for(pj=pi->next,j=i+1;j<n;j++,pj=pj->next)            if(pindex->grade> pj->grade)                pindex=pj;            memcpy(&temp,pi,len);         memcpy(pi,pindex,len);         memcpy(pindex,&temp,len);     }    printf(" Sorting complete ---> ");}void save_info(STU *head){    char filename[20];    FILE *fp;    STU *p;    printf(" Process of saving current information to file \n");    printf(" Please enter filename ：");    scanf("%s",filename);    if((fp=fopen(filename,"w"))==NULL)    {        printf(" Can't open file \n");        return;    }    fprintf(fp," The information of all employees is as follows ：\n full name \t Age \t Working years \t Gender \t marriage \t Level \t Whether or not he is on the job \n");    for(p=head;p!=NULL;p=p->next)    fprintf(fp,"%s\t%d\t%d\t%s\t%s\t%d\t%s\n",p->name,p->age,p->worktime,p->sex,p->marrige,p->grade,p->tired);    fprintf(fp,"%d",0);    fclose(fp);    printf(" Save complete !--->");}void copy(){    FILE *in,*out;    char infile[40],ch;    char outfile[40];    printf(" Now enter the backup of student information file \n");    printf(" The source file name :");    scanf("%s",infile);    printf(" Backup filename :");    scanf("%s",outfile);    if((in=fopen(infile,"r"))==NULL)    {        printf(" The file could not be opened \n");        exit(0);    }    if((out=fopen(outfile,"w"))==NULL)    {        printf(" The file could not be opened \n");        exit(0);    }    ch=fgetc(in);    while(ch!=EOF)    {        fputc(ch,out);        ch=fgetc(in);    }           fclose(in);        fclose(out);        printf(" Backup success !\n");}STU *load_info(){    STU *head=NULL,*pnew,*pend;    char filename[20];    char a[20];    FILE *fp;    int i;    printf("           \t\t File loading employee information , Input file name :");    scanf("%s",filename);    if((fp=fopen(filename,"r"))==NULL)    {        printf("           \t\t Loading failed !\n");        exit(0);    }    for(i=0;i<8;i++)        fscanf(fp,"%s",a);    for(;;)    {        pnew=(STU *)malloc(sizeof(STU));        fscanf(fp,"%s",&pnew->name);            if(strcmp(pnew->name,"0")==0)                break;        fscanf(fp,"%d%d%s%s%d%s",&pnew->age,&pnew->worktime,&pnew->sex,&pnew->marrige,&pnew->grade,&pnew->tired);        pnew->next=NULL;            if(head==NULL)        {            head=pnew;            pend=pnew;        }        else        {            pend->next=pnew;            pend=pnew;        }    }    fclose(fp);    printf("           \t\t Loading successful !\n");    return head;}char *password(){    char password[100],c;    char *result=NULL;    int e,count;    e=0;count=0;    while((c=getch())!=13&&e<100)//13 For carriage return               {                      if(c==8&&e>0)//8 Back off                      {                            password[e--]='\0';// Delete the last one , And the counter decreases 1                            printf("\b \b");// Backspace                      }                     else                     {                            password[e++]=c;                            printf("*");// Cover * Number , When the output space covers the previous character , Move forward again , So that the next time you enter                      }              }             password[e]='\0';             if(strcmp(password,"123456")==0)                result=1;                 return  result;}

Program running effect

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