ioutilities.c

通讯录 C語言

#include "main.h"

/*
  ==================================================
=============================
 	Author:		Hammer, May 2002, For www.cprogramming.com/cboard/
 	File:		ioUtilities.c
 	Contents:	io_GetInt
				io_EnterToContinue
				io_GetYesNo
				io_GetLine
				io_WriteAllRecordsToFile
				io_WriteRecordToFile
				io_LoadAppConfig
				io_SaveAppConfig
  ==================================================
=============================
*/

static FILE *fp;

/*
  ==================================================
=============================
 	Function: 	ioLoadPhoneBookFromFile
    Args: 		Pointer to the node list 
    Returns: 	Pointer to the node list.
    			NULL
    Purpose:	Loads the Record structs from the phone book file into the List
  ==================================================
=============================
*/
struct Node *io_LoadPhoneBookFromFile(struct Node *List)
{
	struct Record	rec, *recptr;
	struct Node		*tmpListPtr;

	if ((fp = fopen(STR_FILENAME, "rb")) == NULL)
	{	/* Failed to open database file */
		printf("ERROR: Unable to open phone book file: %s\n", STR_FILENAME);
		return(List);
	}

	if (List)
	{	/* List not empty, kill it before we start reloading */
		(void)li_Traverse(List, free);
		List = li_Destroy(List);
	}

	while (fread(&rec, sizeof(struct Record), 1, fp) == 1)
	{
		if ((recptr = malloc(sizeof(struct Record))) == NULL)
		{					/* Memory failure, don't do anymore */
			perror("malloc");
			break;
		}

		*recptr = rec;

		if ((tmpListPtr = li_Insert(List, recptr, rec_Compare)) == NULL)
		{
			printf("Error performing insert on list.  Item not addded.\n");
			free(recptr);	/* throw record away */
		}
		else
		{
			List = tmpListPtr;
			recptr->ID = gl_HighestID;
			recptr->Status = (unsigned char)0;
		}
	}

	(void)fclose(fp);
	gl_AppData.DataChanged = FALSE;
	return(List);
}

/*
  ==================================================
=============================
    Function: 	io_GetInt
    Args:		maximum number for user to choose
    Returns: 	Number chosen, or -1 if x or X entered (for menu use)
    Notes:		Assumes that 0 will never be a valid option, and will ask
    			the user to re-enter.
    Purpose:	Get an int from stdin (keyboard).
  ==================================================
=============================
 */
int io_GetInt(int Max)
{
	int		Input, len;
	char	buffer[BUFSIZ];

	for (;;)
	{
		if ((len = io_GetLine(buffer, BUFSIZ, stdin)) != 0)
		{
			if (len == 1 && (buffer[0] == 'x' || buffer[0] == 'X'))
			{	/* Allow for xX to be entered, and return -1 */
				Input = RC_BAD;
				break;
			}

			if ((Input = atoi(buffer)) != 0)
			{
				if (Input >= 1 && Input <= Max)
				{
					break;
				}
			}
		}

		printf("Invalid. Try again (1-%d, x to exit)>", Max);
	}

	return(Input);
}

/*
  ==================================================
=============================
    Function: 	io_EnterToContinue
    Args: 		None
    Returns: 	None
    Purpose:	Simulates the good old DOS PAUSE
  ==================================================
=============================
 */
void io_EnterToContinue(void)
{
	printf("---> Enter To Continue <---");
	FLUSH_INPUT;
}

/*
  ==================================================
=============================
    Function: 	io_GetYesNo
    Args: 		String containing the prompt to be displayed
    Returns: 	TRUE if yY entered, FALSE if nN entered
    Purpose:	Get a Y or N from stdin (keyboard)
  ==================================================
=============================
 */
bool_t io_GetYesNo(char *prompt)
{
	int		c;
	bool_t	rc;

	for (;;)
	{
		printf("%s", prompt);
		c = getchar();
		switch (c)
		{
		case 'y':
		case 'Y':
			rc = TRUE;
			break;
		case 'n':
		case 'N':
			rc = FALSE;
			break;
		default:
			if (c != '\n') FLUSH_INPUT;
			continue;
		}
		break;
	}

	if (c != '\n') FLUSH_INPUT;
	return(rc);
}

/*
  ==================================================
=============================
    Function: 	io_GetLine
    Args: 		buffer to place the text
    			length of the buffer
    			file pointer to read from.
    Returns: 	Chars read and placed into buffer
    Purpose:	Same as fgets() but does not keep the newline character
  ==================================================
=============================
 */
int io_GetLine(char *buffer, int maxlen, FILE *fp)
{
	int		len = 0, c;
	char	*ptr = buffer;
	char	*endptr = buffer + maxlen - 1;

	if (fp != NULL)
	{
		while ((c = fgetc(fp)) != EOF)
		{
			if (c == '\n') break;
			*ptr = c;
			ptr++;
			len++;
			if (ptr == endptr) break;
		}
	}

	*ptr = '\0';
	return(len);
}

/*
  ==================================================
=============================
    Function: 	io_WriteAllRecordsToFile
    Args: 		Pointer to list 
    Returns: 	Number of items written.
    Purpose:	Save all Record structs in the List to a disk file
  ==================================================
=============================
 */int io_WriteAllRecordsToFile(struct Node *List)
{
	unsigned char	status = ST_DELETED;

	if ((fp = fopen(STR_FILENAME, "wb")) == NULL)
	{	/* Failed to open database file */
		printf("ERROR: Unable to open phone book file: %s\n", STR_FILENAME);
		return(0);
	}

	/* First delete dead records from the list, then write them to disk */
	gl_AppData.MainList = li_DeleteNodeAndData(gl_AppData.MainList, &status, rec_CompareStatus);
	(void)li_Traverse(List, io_WriteRecordToFile);

	(void)fclose(fp);

	gl_AppData.DataChanged = FALSE;
	return(gl_HighestID);
}

/*
  ==================================================
=============================
    Function: 	io_WriteRecordToFile
    Args: 		Pointer to record structure to be written.
    Returns: 	Nothing
    Purpose:	Sub-function to write a single Record struct to disk
  ==================================================
=============================
 */
void io_WriteRecordToFile(void *ptr)
{
	struct Record	*rec = ptr;

	if (rec->Status & ST_DELETED) return;	/* Don't save deleted records */

	if (fp == NULL)
	{
		fprintf(stderr, "ERROR: Attempting to write to unopened file\n");
		return;
	}

	if (fwrite(rec, sizeof(struct Record), 1, fp) != 1) perror("WriteRecordToFile");
}

/*
  ==================================================
=============================
    Function: 	io_LoadAppConfig
    Args: 		None
    Returns: 	Nothing
    Purpose:	Loads the appconfig structure from disk
  ==================================================
=============================
 */
void io_LoadAppConfig(void)
{
	FILE				*myfp;
	struct appconfig	tmpcfg;

	if ((myfp = fopen(STR_CFG_FILENAME, "rb")) == NULL) return;
	if (fread(&tmpcfg, sizeof(struct appconfig), 1, myfp) == 1) gl_AppCfg = tmpcfg;

	(void)fclose(myfp);
}

/*
  ==================================================
=============================
    Function: 	io_SaveAppConfig
    Args: 		None
    Returns: 	Nothing
    Purpose:	Saves the appconfig structure to disk
  ==================================================
=============================
 */
void io_SaveAppConfig(void)
{
	FILE	*myfp;

	if ((myfp = fopen(STR_CFG_FILENAME, "wb")) == NULL) return;

	if (fwrite(&gl_AppCfg, sizeof(struct appconfig), 1, myfp) != 1)
		perror (STR_CFG_FILENAME);

	(void)fclose(myfp);
}