It's the first time to write your own program in C language. If you have a boss, you can help a little

For the first time c Language to write their own programs

Is there anyone who can give some advice 0.0（ Changed a mobile number , By the way, I copied the excerpts I wrote before ）

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct goods
{
    
	int num;
	char name[20];
	int price;
    	
}gds;


jiemian()
{
    
printf("\t** Welcome to use ssh Commodity system **\n");
printf("\t************************\n");
printf("\t1. Enter clothing information \n");
printf("\t2. Display clothing information \n");
printf("\t3. Find clothing information \n");
printf("\t4. Insert clothing information \n");
printf("\t5. Delete clothing information \n");
printf("\t6. Sort clothes information \n");
printf("\t7. Exit the system \n");
printf("\t************************\n");
}


jiemian2()
{
    
printf("\t******* To find the way *********\n");
printf("\t************************\n");
printf("\t1. Find by number \n");
printf("\t2. Search by name \n");
printf("\t3. Find by price \n");
printf("\t************************\n");
}


void write_word(gds arr[],int n)
{
    int i=0;
	FILE *fp=NULL;
	fp=fopen("E:\\123.txt","w");
	if(fp==NULL)
	{
    printf("open error\n!");exit(0);}
	while(i<n)
	{
    
		fprintf(fp,"%d\t",arr[i].num);
		fprintf(fp,"%s\t",arr[i].name);
		fprintf(fp,"%d\t",arr[i].price);
		i++;
	}
	fclose(fp);
}


void read_word(gds arr[],int *n)
{
    
	int i=0;
	FILE *fp=NULL;
	fp=fopen("E:\\123.txt","r");
	if(fp==NULL){
    printf("open error!\n");exit(0);}
	while(!feof(fp))
	{
    
		fscanf(fp,"%d",&arr[i].num);
		fscanf(fp,"%s",&arr[i].name);
		fscanf(fp,"%d",&arr[i].price);
		i++;
	}
	*n=i-1;
	fclose(fp);
}



int takein(gds arr[],int n)
{
    
	int i,m;
   printf("\t************************\n");
   printf("\t Please enter the quantity you added ：");
   scanf("%d",&m);
	if(m>0)
	{
    
       for(i=n;i<n+m;i++)
	   {
    
	 	   printf("\t Enter clothing number ：");
           scanf("%d",&arr[i].num);
           printf("\t Enter the clothing name ：");
           scanf("%s",&arr[i].name);
           printf("\t Enter the price of clothes ：");
		   scanf("%d",&arr[i].price);
           printf("\n");
	   }
	 }
	else printf(" This product information does not exist ！");
	printf("\t************************\n");
return n+m;
}


void expose(gds arr[],int n)
{
    
	int i;
	printf("\t Clothing number \t Clothing name \t Clothing price \n");
	for(i=0;i<n;i++,arr++)
	{
    
		printf("\t%4d\t%13s\t%14d\n",arr->num,arr->name,arr->price);

		
	}

}


int search(gds arr[],int n)
{
    
	int i,a=0;
    printf("\t************************\n");
    printf("\t Enter the looking for clothes number ：");
    scanf("%d",&i);
    if(n>0)
	{
    
	   printf("\t Clothing number \t Clothing name \t Clothing price \n");
		while(arr->num!=i&&a<n)
		{
    
		  arr++;a++;   
		} 
		if(a<n){
    
               printf("\t%4d\t%13s\t%14d\n",arr->num,arr->name,arr->price);}
		else printf("\t This product does not exist in the database ！\n");
	}
else printf("\t This product does not exist ！\n");
printf("\t************************\n");
return 0;
}


int insert(gds arr[],int n)
{
    
	int i,a;
	expose(arr,n);
    printf("\t************************\n");
	printf("\t Enter the serial number of the desired insertion position ：");
	scanf("%d",&a);
	if(a>n+1||a<=0){
    
		printf("\t Out of range ！\n");
	}
	else {
    if(0<a<n+1){
    
		for(i=n-1;i>=a-2;i--)
	{
    
		arr[i+1]=arr[i];
		
	}
    printf("\t Enter clothing number ：");
	scanf("%d",&arr[a-1].num);
	printf("\t Enter the clothing name ：");
	scanf("%s",&arr[a-1].name);
	printf("\t Enter the price of clothes ：");
	scanf("%d",&arr[a-1].price);
	}
	else{
    
    printf("\t Enter clothing number ：");
	scanf("%d",&arr[a-1].num);
	printf("\t Enter the clothing name ：");
	scanf("%s",&arr[a-1].name);
	printf("\t Enter the price of clothes ：");
	scanf("%d",&arr[a-1].price);
	}
	printf("\t************************\n");
	n++;}//( For the time being, only one number can be added )
	return n;

}


int reduce(gds arr[],int n)
{
    
    int i,a,b=0;
	expose(arr,n);
    printf("\t************************\n");
	printf("\t Enter the desired deletion number ：");
	scanf("%d",&a);
	for(i=0;i<n;i++)
	{
    
	if(arr[i].num==a)
	{
    
		for(;i<n-1;i++) arr[i]=arr[i+1];
	}
	else b++;
	}
	if(b==n) printf("\t Out of range ！\n");
	else {
     printf("\t Delete successful ！\n");--n;}
	
	
	printf("\t************************\n");
	return n;
}


void sort(gds arr[],int n)// From small to large 
{
    int i,j;
gds k[10];
printf("\t************************\n");
for(i=n-1;i>0;i--)
{
    
	for(j=0;j<i;j++)
	{
    
		if(arr[j].num>arr[j+1].num)
		{
    
			k[1]=arr[j];
		    arr[j]=arr[j+1];
	    	arr[j+1]=k[1];
		}
	}
}
expose(arr,n);
printf("\t************************\n");
}


int search2(gds arr[],int n)
{
    
	char i[20];
	int j=0,b=0;
    printf("\t************************\n");
    printf("\t Enter the name of the clothes you are looking for ：");
    scanf("%s",&i);
    if(n>0)
	{
    
	printf("\t Clothing number \t Clothing name \t Clothing price \n");
	for(j=0;j<n;j++)
	{
    
		if(strcmp(arr[j].name,i)==0)
		{
    
        printf("\t%4d\t%13s\t%14d\n",arr[j].num,arr[j].name,arr[j].price);
		b=1;
		}
	}
	if(j==n&&b==0)printf("\t This product does not exist in the database ！\n");
	}
else printf("\t This product does not exist ！\n");
printf("\t************************\n");
return 0;
}

void search3(gds arr[],int n)
{
    
	int a,b,i,j=0;
	printf("\t************************\n");
    printf("\t Enter the price range of looking for clothes （ Such as 50-100）：");
	scanf("%d-%d",&a,&b);
	if(n>0)
	{
    
	printf("\t Clothing number \t Clothing name \t Clothing price \n");
	for(i=0;i<n;i++)
	{
    
		if(arr[i].price<=b&&arr[i].price>=a)
		{
    printf("\t%4d\t%13s\t%14d\n",arr[i].num,arr[i].name,arr[i].price);j=1;}
	}
	if(i==n&&j==0)printf("\t Out of range ！\n");
	}

	printf("\t************************\n");

}


void method(gds arr[],int n)
{
    
	int a;
   printf("\t************************\n");
   jiemian2();
   printf("\t************************\n");
   printf("\t Enter the action you need ：");
   scanf("%d",&a);
   
   switch (a)
   {
    
       case 1 :search(arr,n);break;
	   case 2 :search2(arr,n);break;
	   case 3 :search3(arr,n);break;
   } 

}


int change(gds arr[],int n)
{
    
	int a,i;
	char b[10];
	printf(" Modify the category name ：");
	scanf("%s",&b);
	printf(" Revise the price ：");
	scanf("%d",&a);
	for(i=0;i<n;i++)
	{
    
	while(strcmp(arr[i].name,b)==0)
	arr[i].price=a;
	}
}


void main()
{
    int n,p=0;
gds arr[100];
read_word(arr,&p);
while(1)
{
    
   printf("\t************************\n");
   jiemian();
   printf("\t************************\n");
   printf("\t Enter the action you need ：");
   scanf("%d",&n);
   
   switch (n)
     {
    
       case 1 :p=takein(arr,p);break;
	   case 2 :expose(arr,p);break;
       case 3 :method(arr,p);break;
       case 4 :p=insert(arr,p);break;
       case 5 :p=reduce(arr,p);break;
	   case 6 :sort(arr,p);break;
	   case 7 :change
       case 8 :write_word(arr,p);exit(0);
   }
getchar();printf("\t Press any key to continue ...");
getchar();system("cls");

}

}

This is a simple small system written in the school training course , There are only a few main functions .
I don't know if there is anything else that can be improved