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/*
* File: error.c
* Purpose: Implement error reporting functions.
* Author: Lars Wirzenius
* Version: "@(#)SeX:$Id: error.c,v 1.1 1996/01/05 13:16:05 liw Exp $"
*/
#include <stdarg.h>
#include <stdio.h>
#include "error.h"
/*
* Variables: error_list, error_count, error_start
* Purpose: List of error messages.
* Note: This shouldn't be dynamic, since that introduces more
* possibilities for errors.
*/
#define MAX_ERRORS 2
#define MAX_ERROR_LEN 200
static struct {
char msg[MAX_ERROR_LEN];
struct win *win;
} error_list[MAX_ERRORS];
static int error_count = 0;
static int error_start = 0;
/*
* Function: error
* Purpose: Add new error to queue of error messages.
* Arguments: win the window for which the error occurred
* (NULL means relevant to all windows)
* other arguments are like in printf.
* Return: Nothing.
* Note: The output may not be more than MAX_ERROR_LEN-1 characters.
*/
void error(struct win *win, const char *fmt, ...) {
va_list args;
int i;
static FILE *devnull = NULL;
int n;
if (error_count == MAX_ERRORS)
error_start = (error_start + 1) % MAX_ERRORS;
i = (error_start + error_count) % MAX_ERRORS;
++error_count;
if (devnull == NULL) {
devnull = fopen("/dev/null", "w");
if (devnull == NULL) {
sprintf(error_list[i].msg, "couldn't open /dev/null");
return;
}
}
va_start(args, fmt);
n = vfprintf(devnull, fmt, args);
va_end(args);
if (n >= MAX_ERROR_LEN)
sprintf(error_list[i].msg, "error message too long");
else {
va_start(args, fmt);
vsprintf(error_list[i].msg, fmt, args);
error_list[i].win = win;
va_end(args);
}
}
/*
* Function: next_error
* Purpose: Return next error message and remove it from list.
* Arguments: win the window for which messages should be reported
* Return: Pointer to string, NULL if none.
* Note: The string will be overwritten by a future call to error.
*/
char *next_error(struct win *win) {
char *p;
if (error_count == 0)
return NULL;
p = error_list[error_start].msg;
error_start = (error_start + 1) % MAX_ERRORS;
--error_count;
return p;
}
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