delete.cpp

一个国外学生做的基于Web浏览器的email程序

#include "webemail.h"
#include "delete.h"

void deletemail(char path[], int mailnumber)
{
	passwd *info;
	FILE *data;
	FILE *tmp;

	char tmpname[400];

	char buf[500];

	int emailcount = 0;
	char *env;	

	info=getpwnam(globaluser);

	snprintf(tmpname, 400, "%s/.webmail/tmp", info->pw_dir);

	data = fopen(path, "r");
	if (data == NULL)
	{
		error("deletemail():Error opening data for read");
		return;
	}
	if (bothlock(data, 'r')!=0)
	{
		fclose(data);
		error("deletemail():Error locking data for read");
		return;
	}
	tmp = fopen(tmpname, "w");
	if (tmp == NULL)
	{
		error("deletemail():error opening temp for write");
		fclose(data);
		return;
	}
	if (bothlock(tmp, 'w')!=0)
	{
		fclose(tmp);
		fclose(data);
		error("deletemail():error locking temp for write");
		return;
	}
	while (fgets(buf, 499, data) != NULL)
	{
		fputs(buf, tmp);
	}

	fclose(data);
	fclose(tmp);

	data = fopen(path, "w");
	if (data == NULL)
	{
		error("deletemail():Error opening data for write");
		return;
	}

	tmp = fopen(tmpname, "r");
	if (tmp == NULL)
	{
		fclose(data);
		error("deletemail():error opening temp for read");
		return;
	}
	
	while (fgets(buf, 499, tmp) != NULL)
	{
		if (strncmp(buf, "From ", 5)==0)
		{
			emailcount++;
		}
		if (emailcount != mailnumber)
		{
			fputs(buf, data);
		}
	}

	bothunlock(tmp);
	fclose(tmp);
	bothunlock(data);
	fclose(data);

	remove(tmpname);

	return;
}
void removeaddr(int emailnumber) //remove address
{
	passwd *info;
	FILE *book;
	FILE *tmp;
	char bookname[400];
	char tmpname[400];
	int number = 0; //one to delete
	int count = 0;
	char *env;
	char data[500];

	if (emailnumber < 0)
	{
		if ((env = getenv("QUERY_STRING"))==NULL)
		{
			address();
			return;
		}
		number = atoi(env+11);
	}
	else
	{
		number = emailnumber;
	}
	info=getpwnam(globaluser);
	snprintf(bookname, 400, "%s/.webmail/book", info->pw_dir);
	snprintf(tmpname, 400, "%s/.webmail/tmp", info->pw_dir);

	book = fopen(bookname, "r");
	if (book == NULL)
	{
		error("removeaddr():Error opening book for read");
		return;
	}
	if (bothlock(book, 'r')!=0)
	{
		fclose(book);
		error("removeaddr():Error locking book for read");
		return;
	}
	tmp = fopen(tmpname, "w");
	if (tmp == NULL)
	{
		error("removeaddr():Error opening tmp for write");
		return;
	}
	if (bothlock(tmp, 'w')!=0)
	{
		fclose(book);
		fclose(tmp);
		error("removeaddr():Error locking tmp for write");
		return;
	}

	while(fgets(data, 499, book)!=NULL)
	{
		count++;
		if (count < (number-1)*7+1 || count > number*7)
			fputs(data, tmp);
	}

	bothunlock(book);
	fclose(book);
	fflush(tmp);
	fdatasync(fileno(tmp));
	bothunlock(tmp);
	fclose(tmp);


	rename(tmpname, bookname);

	if (emailnumber < 0)
	{
		cout << "content-type: text/html" << endl;
		cout << "Pragma: No-Cache" << endl << endl;
		disjavascript("?book", "Address deleted", "address book");
	}
	sync();
	return;
}