misc.c

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/*
 * Miscellaneous routines.
 */

#include "sysincludes.h"
#include "msdos.h"
#include "stream.h"
#include "vfat.h"
#include "mtools.h"


void printOom(void)
{
        fprintf(stderr, "Out of memory error");
}

char *get_homedir(void)
{
        struct passwd *pw;
        uid_t uid;
        char *homedir;
        char *username;
        
        homedir = getenv ("HOME");    
        /* 
         * first we call getlogin. 
         * There might be several accounts sharing one uid 
         */
        if ( homedir )
                return homedir;
        
        pw = 0;
        
        username = getenv("LOGNAME");
        if ( !username )
                username = getlogin();
        if ( username )
                pw = getpwnam( username);
  
        if ( pw == 0 ){
                /* if we can't getlogin, look up the pwent by uid */
                uid = geteuid();
                pw = getpwuid(uid);
        }
        
        /* we might still get no entry */
        if ( pw )
                return pw->pw_dir;
        return 0;
}


static void get_mcwd_file_name(char *file)
{
        char *mcwd_path;
        char *homedir;

        mcwd_path = getenv("MCWD");
        if (mcwd_path == NULL || *mcwd_path == '\0'){
                homedir= get_homedir();
                if(!homedir)
                        homedir="/tmp";
                strncpy(file, homedir, MAXPATHLEN-6);
                file[MAXPATHLEN-6]='\0';
                strcat( file, "/.mcwd");
        } else {
                strncpy(file, mcwd_path, MAXPATHLEN);
                file[MAXPATHLEN]='\0';
        }
}

void unlink_mcwd()
{
        char file[MAXPATHLEN+1];
        get_mcwd_file_name(file);
        unlink(file);
}

FILE *open_mcwd(const char *mode)
{
        struct stat sbuf;
        char file[MAXPATHLEN+1];
        time_t now;
        
        get_mcwd_file_name(file);
        if (*mode == 'r'){
                if (stat(file, &sbuf) < 0)
                        return NULL;
                /*
                 * Ignore the info, if the file is more than 6 hours old
                 */
                getTimeNow(&now);
                if (now - sbuf.st_mtime > 6 * 60 * 60) {
                        fprintf(stderr,
                                "Warning: \"%s\" is out of date, removing it\n",
                                file);
                        unlink(file);
                        return NULL;
                }
        }
        
        return  fopen(file, mode);
}
        

/* Fix the info in the MCWD file to be a proper directory name.
 * Always has a leading separator.  Never has a trailing separator
 * (unless it is the path itself).  */

const char *fix_mcwd(char *ans)
{
        FILE *fp;
        char *s;
        char buf[MAX_PATH];

        fp = open_mcwd("r");
        if(!fp){
                strcpy(ans, "A:/");
                return ans;
        }

        if (!fgets(buf, MAX_PATH, fp))
                return("A:/");

        buf[strlen(buf) -1] = '\0';
        fclose(fp);
                                        /* drive letter present? */
        s = skip_drive(buf);
        if (s > buf) {
                strncpy(ans, buf, s - buf);
                ans[s - buf] = '\0';
        } else 
                strcpy(ans, "A:");
                                        /* add a leading separator */
        if (*s != '/' && *s != '\\') {
                strcat(ans, "/");
                strcat(ans, s);
        } else
                strcat(ans, s);

#if 0
                                        /* translate to upper case */
        for (s = ans; *s; ++s) {
                *s = toupper(*s);
                if (*s == '\\')
                        *s = '/';
        }
#endif
                                        /* if only drive, colon, & separator */
        if (strlen(ans) == 3)
                return(ans);
                                        /* zap the trailing separator */
        if (*--s == '/')
                *s = '\0';
        return ans;
}

void *safe_malloc(size_t size)
{
        void *p;

        p = malloc(size);
        if(!p){
                printOom();
                exit(1);
        }
        return p;
}

void print_sector(char *message, unsigned char *data, int size)
{
        int col;
        int row;

        printf("%s:\n", message);
        
        for(row = 0; row * 16 < size; row++){
                printf("%03x  ", row * 16);
                for(col = 0; col < 16; col++)                   
                        printf("%02x ", data [row*16+col]);
                for(col = 0; col < 16; col++) {
                        if(isprint(data [row*16+col]))
                                printf("%c", data [row*16+col]);
                        else
                                printf(".");
                }
                printf("\n");
        }
}


time_t getTimeNow(time_t *now)
{
        static int haveTime = 0;
        static time_t sharedNow;

        if(!haveTime) {
                time(&sharedNow);
                haveTime = 1;
        }
        if(now)
                *now = sharedNow;
        return sharedNow;
}

char *skip_drive(const char *filename)
{
        char *p;

        /* Skip drive name.  Return pointer just after the `:', or a pointer
         * to the start of the file name if there is is no drive name.
         */
        p = strchr(filename, ':');
        return (p == NULL || p == filename) ? (char *) filename : p + 1;
}

char *get_drive(const char *filename, const char *def)
{
        const char *path;
        char *drive;
        const char *rest;
        size_t len;

        /* Return the drive name part of a full filename. */

        path = filename;
        rest = skip_drive(path);
        if (rest == path) {
                if (def == NULL) def = "A:";
                path = def;
                rest = skip_drive(path);
                if (rest == path) {
                        path = "A:";
                        rest = path+2;
                }
        }
        len = rest - path;
        drive = safe_malloc(len * sizeof(drive[0]));
        len--;
        memcpy(drive, path, len);
        drive[len] = 0;
        if (len == 1) drive[0] = toupper(drive[0]);
        return drive;
}

#if 0

#undef free
#undef malloc

static int total=0;

void myfree(void *ptr)
{
        int *size = ((int *) ptr)-1;
        total -= *size;
        fprintf(stderr, "freeing %d bytes at %p total alloced=%d\n",
                *size, ptr, total);
        free(size);
}

void *mymalloc(size_t size)
{
        int *ptr;
        ptr = (int *)malloc(size+sizeof(int));
        if(!ptr)
                return 0;
        *ptr = size;
        ptr++;
        total += size;
        fprintf(stderr, "allocating %d bytes at %p total allocated=%d\n",
                size, ptr, total);
        return (void *) ptr;
}

void *mycalloc(size_t nmemb, size_t size)
{
        void *ptr = mymalloc(nmemb * size);
        if(!ptr)
                return 0;
        memset(ptr, 0, size);
        return ptr;
}

void *myrealloc(void *ptr, size_t size)
{
        int oldsize = ((int *)ptr) [-1];
        void *new = mymalloc(size);
        if(!new)
                return 0;
        memcpy(new, ptr, oldsize);
        myfree(ptr);
        return new;
}

char *mystrdup(char *src)
{
        char *dest;
        dest = mymalloc(strlen(src)+1);
        if(!dest)
                return 0;
        strcpy(dest, src);
        return dest;
}


#endif

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