log.c

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/* log.c
 *
 * Copyright (c) 1992-2001 by Mike Gleason.
 * All rights reserved.
 *
 */
 
#include "syshdrs.h"
 
#include "util.h"
#include "log.h"
 
extern int gMaxLogSize;
char gLogFileName[256];
 
extern char gOurDirectoryPath[];
 
 
void
InitLog(void)
{
    OurDirectoryPath(gLogFileName, sizeof(gLogFileName), kLogFileName);
}   /* InitLog */
 
 
 
void
LogXfer(const char *const mode, const char *const url)
{
    FILE *fp;
 
    if (gMaxLogSize == 0)
        return;     /* Don't log */
 
    fp = fopen(gLogFileName, FOPEN_APPEND_TEXT);
    if (fp != NULL) {
        (void) fprintf(fp, "  %s %s\n", mode, url);
        (void) fclose(fp);
    }
}   /* LogOpen */
 
 
 
void
LogOpen(const char *const host)
{
    time_t now;
    FILE *fp;
 
    if (gMaxLogSize == 0)
        return;     /* Don't log */
 
    time(&now);
    fp = fopen(gLogFileName, FOPEN_APPEND_TEXT);
    if (fp != NULL) {
        (void) fprintf(fp, "%s at %s", host, ctime(&now));
        (void) fclose(fp);
    }
}   /* LogOpen */
 
 
 
 
void
EndLog(void)
{
    FILE *new, *old;
    struct Stat st;
    long fat;
    char str[512];
    char tmpLog[256];
 
    if (gOurDirectoryPath[0] == '\0')
        return;     /* Don't create in root directory. */
 
    /* If the user wants to, s/he can specify the maximum size of the log file,
     * so it doesn't waste too much disk space.  If the log is too fat, trim the
     * older lines (at the top) until we're under the limit.
     */
    if ((gMaxLogSize <= 0) || (Stat(gLogFileName, &st) < 0))
        return;                        /* Never trim, or no log. */
 
    if ((size_t)st.st_size < (size_t)gMaxLogSize)
        return;                        /* Log size not over limit yet. */
 
    if ((old = fopen(gLogFileName, FOPEN_READ_TEXT)) == NULL)
        return;
 
    /* Want to make it so we're about 30% below capacity.
     * That way we won't trim the log each time we run the program.
     */
    fat = (long) st.st_size - (long) gMaxLogSize + (long) (0.30 * gMaxLogSize);
    while (fat > 0L) {
        if (fgets(str, (int) sizeof(str), old) == NULL)
            return;
        fat -= (long) strlen(str);
    }
    /* skip lines until a new site was opened */
    for (;;) {
        if (fgets(str, (int) sizeof(str), old) == NULL) {
            (void) fclose(old);
            (void) remove(gLogFileName);
            return;                    /* Nothing left, start anew next time. */
        }
        if (! isspace(*str))
            break;
    }
 
    /* Copy the remaining lines in "old" to "new" */
    OurDirectoryPath(tmpLog, sizeof(tmpLog), "log.tmp");
    if ((new = fopen(tmpLog, FOPEN_WRITE_TEXT)) == NULL) {
        (void) fclose(old);
        return;
    }
    (void) fputs(str, new);
    while (fgets(str, (int) sizeof(str), old) != NULL)
        (void) fputs(str, new);
    (void) fclose(old);
    (void) fclose(new);
    if (remove(gLogFileName) < 0)
        return;
    if (rename(tmpLog, gLogFileName) < 0)
        return;
}   /* EndLog */