A computer manage program

This is a program to organize computer’s usage using C99 language with a command line interface. It uses malloc to allocate information, and has a shell interaction interface. See more about its functionality by clicking read more.

This program is done in a pretty early stage. I didn’t officially learn C at that time. So, most of stuff are based on self-learning and it might have certain problems, like efficiency, possible memory leaking, some unconverted floating point number out of flow.

Designed functions:

(1) Input function: input the student number, class, name and computer start time. Program would provide multiple ways to ask for the input, batch input could accept multiple lines information that follows certain format. The name is designed to accept UTF-8 characters and it is demoed as using UTF-8 characters.

(2) Calculation function: calculate the cost of each student off the computer, 1 yuan per hour.

(operation cost = operation time * 1.0/h, less than one hour is calculated as one hour)

(3) Query function: according to the conditions (class, student number, name) to display the student’s computer time.

(4) Display of machine usage (the display mode is not limited, but it should be clear at a glance)

Interactions:

Basically, it is a command line program (shell like) that is able to interact by typing the corresponding information. You have the following choices at each run:

Usage:
Type 's' to show all avaliable status.
Type 'o' for student's leave.
Type 'f' to find.
Type 'p' to show all computers.
Type 'a' for student's arrive.
Type 'h' for help.
Type 'q' for quit.

Different function will have different subcommand, like f will ask you to find by class, student number, or name. And a will ask you for batch adding or add a single one.

Features

• Built with C99, most of function are as low as I could, like operate on memory level. So, it should be efficient in memory usage.
• Using low level comparison, like bitwise, in the program. So, it is precise.
• Have batch add feature, if the user put a serious of data in one time, it is able to import all data once. This function is for implementing adding and saving to file in the future.

Source code

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <time.h>
#include <math.h>

/*
NEED FIX: 
1.wrong message catch
2.read from file
3.Time can only be 1970-1-1 -- 2030-1-1
4.class_num type has limited fit
5.offline should check first
*/

typedef unsigned long long u64;
typedef unsigned int u32;
typedef unsigned short u16;

typedef struct {
            u16 index;
            u32 class_num;			
			time_t start_time;	//save definite time. From 1970-1-1 REMINDER: THIS IS FINAL STORED ABSOLUTE TIME.
			time_t end_time;			
			u64 stu_id;
			u16 flag;
			char *name;        
}data;
void Show_ava();

int len_data = 60;
data *tt[60];
#define CMD_BUFFER_LEN 80


int ceil_altenate(double a){
	int g=(int)a;
	if((a-g)>0) return (int)(a+1);
	return (int)a;
}

//use money rule to calculate money need to charge
//this function only calculate, it will not modify any value in the struct.
int charge(u16 index){
	time_t end;
	time(&end);
	if(!tt[index]->start_time) return 0;
	if(!(tt[index]->flag))	return ceil_altenate(((double)(end-tt[index]->start_time)/3600.0));
	return ceil_altenate(((double)(tt[index]->end_time-tt[index]->start_time)/3600.0));
}

//print only one object
void print_one(u16 i) {
	if (!((i < len_data)&(i >= 0))) {
		printf("Invalid!!!\n");
	}else if(!tt[i]->start_time){
		printf("  | %2d |  %-6s  | %5d | %12lld |  %04d-%02d-%02d %02d:%02d:%02d |", tt[i]->index + 1, tt[i]->name, tt[i]->class_num, tt[i]->stu_id,
			0, 0, 0, 0, 0, 0);
		printf("%04d-%02d-%02d %02d:%02d:%02d |   %2d   |  %d   |\n",0, 0, 0, 0, 0, 0,charge(tt[i]->index), tt[i]->flag);
	}else if (!(tt[i]->flag)) {
				struct tm *ptminfo_start=(struct tm *)malloc(sizeof(struct tm *));
				ptminfo_start=localtime(&tt[i]->start_time);
				printf("  | %2d |  %-6s  | %5d | %12lld |  %02d-%02d-%02d %02d:%02d:%02d |",tt[i]->index+1,tt[i]->name,tt[i]->class_num,tt[i]->stu_id,
					ptminfo_start->tm_year + 1900, ptminfo_start->tm_mon + 1, ptminfo_start->tm_mday,  
					ptminfo_start->tm_hour, ptminfo_start->tm_min, ptminfo_start->tm_sec);
				//free(ptminfo_start);
				time_t end;
				struct tm *ptminfo = (struct tm *)malloc(sizeof(struct tm *));
				time(&end);  
				ptminfo=localtime(&end);
			
				  printf("%02d-%02d-%02d %02d:%02d:%02d |   %2d   |  %d   |\n",
					ptminfo->tm_year + 1900, ptminfo->tm_mon + 1, ptminfo->tm_mday,  ptminfo->tm_hour, ptminfo->tm_min, ptminfo->tm_sec,
					charge(tt[i]->index),tt[i]->flag);
				  //free(ptminfo);
			}else{
				struct tm *ptminfo_start = (struct tm *)malloc(sizeof(struct tm *));
				ptminfo_start=localtime(&tt[i]->start_time);

				printf("  | %2d |  %-6s  | %5d | %12lld |  %02d-%02d-%02d %02d:%02d:%02d |",tt[i]->index+1,tt[i]->name,tt[i]->class_num,tt[i]->stu_id,
					ptminfo_start->tm_year + 1900, ptminfo_start->tm_mon + 1, ptminfo_start->tm_mday,  
					ptminfo_start->tm_hour, ptminfo_start->tm_min, ptminfo_start->tm_sec);
				//free(ptminfo_start);
				struct tm *ptminfo = (struct tm *)malloc(sizeof(struct tm *));
				ptminfo=localtime(&tt[i]->end_time);
				
				  printf("%02d-%02d-%02d %02d:%02d:%02d |   %2d   |  %d   |\n",
					ptminfo->tm_year + 1900, ptminfo->tm_mon + 1, ptminfo->tm_mday,  ptminfo->tm_hour, ptminfo->tm_min, ptminfo->tm_sec,
					charge(tt[i]->index),tt[i]->flag);
				//  free(ptminfo);
	}
}

/*Beginning of the finding part*/
//strcmp() : compare two string with case sensitive
void Find_class(u32 cla){
	int i;
	u16 statu = 1;
	//print header
	printf("  | #. |   Name   | Class |  Student ID  |     Start Time       |       End Time     | Charge | Flag |\n");
	for(i=0;i<len_data;i++){
		if(!(tt[i]->class_num ^ cla)){
			statu=0;//Founded
			print_one(i);
		}
	}
	if(statu) printf("  |No such catalog!\n");
}

void Find_name(char *nam){
	int i;
	u16 statu = 1;
	//print header
	printf("  | #. |   Name   | Class |  Student ID  |     Start Time       |       End Time     | Charge | Flag |\n");
	for(i=0;i<len_data;i++){
		if(!strcmp(tt[i]->name,nam)){//This will return the difference between them(Not true means no difference!!!)s
			statu=0;//Founded
			print_one(i);
		}
	}
	if(statu) printf("  |No such catalog!\n");
}

void Find_stu_id(u64 id){
	int i;
	u16 statu = 1;
	//print header
	printf("  | #. |   Name   | Class |  Student ID  |     Start Time       |       End Time     | Charge | Flag |\n");
	for(i=0;i<len_data;i++){
		if(!(id ^ tt[i]->stu_id)){
			statu=0;//Founded
			print_one(i);
		}
	}
	if(statu) printf("  |No such catalog!\n");
}
/*End of finding part.*/

/*Begining of sub-add part*/

//use avaliable computers right now. let student choose which computer. Use loop & flag.
//Add a student and start time calculation.
//Use current system time as the begining time.
void add_stu(){
	printf("Now, we are going to guide you to add a record...\nHere are avaliable status of seats right now:\n");
	Show_ava();
	int statu=1;
	u16 No;
	do{
	if(statu){
		printf("Choose the one you prefer(type the No. of the seat):");
	}else{
		printf("Sorry. There is somebody here. Please choose another seat:");
	}
	statu=0;
	scanf(" %hd",&No);
	No--;
	while (!((No < len_data)&(No >= 0))) {
		printf("Invalid No. Type again:");
		scanf(" %hd", &No);
		No--;
	}
	}while(!(tt[No]->flag));
	getchar();
	printf("Next, we need some basic information of you...\nPlease type your class number:");
	u32 No_c;
	scanf(" %d",&No_c);
	getchar();
	printf("Please type your name:");
	char *na=(char *)malloc(sizeof(char *)+10);
	scanf("%s",na);
	printf("Please type your student id:");
	u64 stu;
	scanf(" %lld",&stu);
	time_t rawtime;  
    time(&rawtime);  
	//to main part to add
	tt[No]->flag=0;
	tt[No]->index=No;
	tt[No]->stu_id=stu;
	tt[No]->class_num=No_c;
	tt[No]->start_time=rawtime;
	tt[No]->end_time=0;
	//printf("%x\n",&tt[No]->name);
	//printf("Before:tt[No]->name:%x,na:%x\n",tt[No]->name,na);
	//free(tt[No]->name);
	tt[No]->name=na;
	//printf("After:tt[No]->name:%x,na:%x\n",tt[No]->name,na);
	printf("Sucessfully add!\n");
	//free(ha);
}

//use when import data
void add_batch(){
	printf("<--Description here-->\nBatch import format: No. class student-id name.\nPlease re-enter for two times after finished to make sure you don't have any more data.\nFor example:1	1507	201540070107	aaa\n");
	getchar();
	int success=0;
	int fail=0;
	short int No=0;
	int No_c=0;
	long long int stu=0;
	char cmd_buffer[80];
	char *read_success;   
  	read_success = fgets(cmd_buffer, 80, stdin);
  	long long int bak=1;
while(!(read_success==NULL)){
char *na=(char *)malloc(sizeof(char *)+10);
sscanf(cmd_buffer, " %hd %d %lld %s ", &No,&No_c,&stu,na);
if(bak==stu) break;
//printf(" %hd %d %lld %s ------\n", No,No_c,stu,na);
No--;
		if(!((No<len_data)&(No>=0))){
			printf("No such computer.\n");
			fail++;
		}else if(!(tt[No]->flag)){
			printf("Sorry, somebody is already here.\n");
			fail++;
		}else{
			time_t rawtime;
    		time(&rawtime);
			tt[No]->flag=0;
			tt[No]->index=No;
			tt[No]->stu_id=stu;
			tt[No]->class_num=No_c;
			tt[No]->start_time=rawtime;
			tt[No]->end_time=0;
			tt[No]->name=na;
			success++;
			printf("Sucessfully add!\n");
		}
	read_success = fgets(cmd_buffer, 80, stdin);
	bak=stu;
	}
	printf("Success:%d,fail:%d,success rate:%.2f%%\n",success,fail,((double)success/(double)(success+fail))*100);
}

/*End of sub-add part*/


/*Begining of the function part*/


void add(){
	printf("Type 'b' to add by batch.\nType 'g' to add with guidence.\nPlease type:\n");
	char a;
	scanf("%c",&a);
	fflush(stdin);
	switch(a){
		case 'b': case 'B':
			add_batch();
		break;
		case 'g': case 'G': 
			add_stu();
		break;
		default: 
			printf("Wrong option.Type 'h' for help.\n"); 
		break;	
	}
}

//print out all computer, nomatter in use or not in use. And also student detail information
void print_all(){
	printf("  | #. |   Name   | Class |  Student ID  |     Start Time       |       End Time     | Charge | Flag |\n");
	int i;
	for(i=0;i<len_data;i++) print_one(i);
}

//a main find function, which will help user choose a specific find function.
void Find(){
	printf("Type 'c' to find by class.\nType 'n' to find by name.\nType 's' to find by student id.\nPlease type:\n");
	char a;
	char *b = (char *)malloc(sizeof(char *) + 10);
	scanf("%c",&a);
	fflush(stdin);
	switch(a){
		case 'c': case 'C': 
			printf("Type message:");
			u32 gh;
			scanf(" %d",&gh);
			getchar();
			Find_class(gh); 
		break;
		case 'n': case 'N': 
			printf("Type message:");
			scanf("%s",b);
			getchar();
			Find_name(b);
			free(b);
		break;
		case 's': case 'S': 
			printf("Type message:");
			u64 gha;
			scanf(" %lld",&gha);
			getchar();
			Find_stu_id(gha); 
		break;
		default: 
			printf("Wrong option.Type 'h' for help.\n"); 
		break;	
	}
}

//delete student who are no longer in use. Set flag to 1 and end time to current
void offline(){
	printf("Type No. of computer:");
	u16 u;
	scanf(" %hd",&u);
	u--;
	time_t rawtime;  
    time(&rawtime); 
	tt[u]->flag=1;
	tt[u]->end_time=rawtime;
}

//Print out avaliable computer.
//When all computers are in use, show no avaliable
void Show_ava(){
	int i;
	u16 statu=0;
	printf("<--Avaliable status-->\n1--Avaliable 0--Unavaliable\n");
	printf("|---------|---------|---------|---------|---------|\n");
	for(i=0;i<len_data;i++){
		if((len_data-i)<5){statu=1; break;}
		printf("|  No.%2d  |  No.%2d  |  No.%2d  |  No.%2d  |  No.%2d  |\n",(i+1),(i+2),(i+3),(i+4),(i+5));
		printf("|    %d    |    %d    |    %d    |    %d    |    %d    |\n",tt[i]->flag,tt[i+1]->flag,tt[i+2]->flag,tt[i+3]->flag,tt[i+4]->flag);
		printf("|---------|---------|---------|---------|---------|\n");
		i+=4;
	}
	if(statu){
	printf("|---------|---------|---------|---------|---------|\n");
	int temp = i;
	for(;i<len_data;i++){
		printf("|  No.%2d  ",(i+1));
	}
	printf("|\n");
	i = temp;
	for(;i<len_data;i++){
		printf("|    %d    ",tt[i]->flag);
	}
	printf("|\n");
	}
}

/*End of function part*/




/*System running part*/

void execute_help(){
	printf("Usage:\n\tType 's' to show all avaliable status.\n\tType 'o' for student's leave.\n\tType 'f' to find.\n\tType 'p' to show all computers.\n\tType 'a' for student's arrive.\n\tType 'h' for help.\n\tType 'q' for quit.\n");
}

//deliver to specific function
int execute_main(char cmd_char){
	switch(cmd_char){
		case 's': case 'S': Show_ava(); break;
		case 'o': case 'O': offline(); break;	
		case 'f': case 'F': Find(); break;
		case 'p': case 'P': print_all(); break;	
		case 'a': case 'A': add(); break;	
		case 'h': case 'H': execute_help(); break;	
		case 'q': case 'Q': {
			int u=0;
			for(u=0;u<len_data;u++){
				//free(tt[u]->name);
				free(tt[u]);
			}
			exit(0); 
			break;			
			}
		default: printf("Wrong option.Type 'h' for help.\n"); break;	
	}
	return 1;
}
/*End of system running part*/

int run(){
	char cmd_char;
	char cmd_buffer[CMD_BUFFER_LEN];
	char *read_success;   
  	read_success = fgets(cmd_buffer, CMD_BUFFER_LEN, stdin);
	if (read_success == NULL) {
		return 1;  
	} else if (sscanf(cmd_buffer, " %c", &cmd_char) == 1) {
		fflush(stdin);
		execute_main(cmd_char);
	} else {	
		fflush(stdin);
		return 1;
	}
	fflush(stdin);
	return 1;
}

//Program will initialize all struct. Assume 60 computers at first. Users can expand it when running by type e. 
int main(int argc, char *argv[]){
int i;
for(i=0;i<len_data;i++){
	//initialize part
	tt[i]=(data *)malloc(sizeof(data)+10);
	tt[i]->flag=1;
	tt[i]->index=i;
	tt[i]->stu_id=0;
	tt[i]->class_num=0;
	tt[i]->start_time=0;
	tt[i]->end_time=0;
	tt[i]->name=(char *)malloc(sizeof(char *)+10);
	char *na = (char *)malloc(sizeof(char *) + 10);
	na = "   ";
	tt[i]->name = na;
}

char *prompt = "$> ";
	printf("Management Application. Author:\n<--Description part-->\n");
	execute_help();
	printf("%s",prompt);
while(run()){
printf("%s",prompt);
fflush(stdin);
}

return 0;
}