minix3/commands/cleantmp/cleantmp.c

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2020-02-21 00:59:27 +05:30
/* cleantmp 1.6 - clean out a tmp dir. Author: Kees J. Bot
* 11 Apr 1991
*/
#define nil 0
#include <sys/types.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <string.h>
#include <time.h>
#include <dirent.h>
#include <errno.h>
#define arraysize(a) (sizeof(a) / sizeof((a)[0]))
#define arraylimit(a) ((a) + arraysize(a))
#ifndef S_ISLNK
/* There were no symlinks in medieval times. */
#define lstat stat
#endif
#ifndef DEBUG
#ifndef NDEBUG
#define NDEBUG
#endif
#endif
#include <assert.h>
#define SEC_DAY (24 * 3600L) /* A full day in seconds */
#define DOTDAYS 14 /* Don't remove tmp/.* in at least 14 days. */
void report(const char *label)
{
fprintf(stderr, "cleantmp: %s: %s\n", label, strerror(errno));
}
void fatal(const char *label)
{
report(label);
exit(1);
}
void *alloc(size_t s)
{
void *mem;
if ((mem= (void *) malloc(s)) == nil) fatal("");
return mem;
}
int force= 0; /* Force remove all. */
int debug= 0; /* Debug level. */
void days2time(unsigned long days, time_t *retired, time_t *dotretired)
{
struct tm *tm;
time_t t;
time(&t);
tm= localtime(&t);
tm->tm_hour= 0;
tm->tm_min= 0;
tm->tm_sec= 0; /* Step back to midnight of this day. */
t= mktime(tm);
if (t < (days - 1) * SEC_DAY) {
*retired= *dotretired= 0;
} else {
*retired= t - (days - 1) * SEC_DAY;
*dotretired= t - (DOTDAYS - 1) * SEC_DAY;
if (*dotretired > *retired) *dotretired= *retired;
}
if (debug >= 2) fprintf(stderr, "Retired: %s", ctime(retired));
if (debug >= 2) fprintf(stderr, "Dotretired: %s", ctime(dotretired));
}
/* Path name construction, addpath adds a component, delpath removes it.
* The string 'path' is used throughout the program as the file under
* examination.
*/
char *path; /* Path name constructed in path[]. */
int plen= 0, pidx= 0; /* Lenght/index for path[]. */
void addpath(int *didx, const char *name)
/* Add a component to path. (name may also be a full path at the first call)
* The index where the current path ends is stored in *pdi.
*/
{
if (plen == 0) path= (char *) alloc((plen= 32) * sizeof(path[0]));
*didx= pidx; /* Record point to go back to for delpath. */
if (pidx > 0 && path[pidx-1] != '/') path[pidx++]= '/';
do {
if (*name != '/' || pidx == 0 || path[pidx-1] != '/') {
if (pidx == plen &&
(path= (char *) realloc((void *) path,
(plen*= 2) * sizeof(path[0]))) == nil
) fatal("");
path[pidx++]= *name;
}
} while (*name++ != 0);
--pidx; /* Put pidx back at the null. The path[pidx++]= '/'
* statement will overwrite it at the next call.
*/
assert(pidx < plen);
}
void delpath(int didx)
{
assert(0 <= didx);
assert(didx <= pidx);
path[pidx= didx]= 0;
}
struct file {
struct file *next;
char *name;
};
struct file *listdir(void)
{
DIR *dp;
struct dirent *entry;
struct file *first, **last= &first;
if ((dp= opendir(path)) == nil) {
report(path);
return nil;
}
while ((entry= readdir(dp)) != nil) {
struct file *new;
if (strcmp(entry->d_name, ".") == 0
|| strcmp(entry->d_name, "..") == 0) continue;
new= (struct file *) alloc(sizeof(*new));
new->name= (char *) alloc((size_t) strlen(entry->d_name) + 1);
strcpy(new->name, entry->d_name);
*last= new;
last= &new->next;
}
closedir(dp);
*last= nil;
return first;
}
struct file *shorten(struct file *list)
{
struct file *junk;
assert(list != nil);
junk= list;
list= list->next;
free((void *) junk->name);
free((void *) junk);
return list;
}
/* Hash list of files to ignore. */
struct file *ignore_list[1024];
size_t n_ignored= 0;
unsigned ihash(const char *name)
/* A simple hashing function on a file name. */
{
unsigned h= 0;
while (*name != 0) h= (h * 0x1111) + *name++;
return h & (arraysize(ignore_list) - 1);
}
void do_ignore(int add, const char *name)
/* Add or remove a file to/from the list of files to ignore. */
{
struct file **ipp, *ip;
ipp= &ignore_list[ihash(name)];
while ((ip= *ipp) != nil) {
if (strcmp(name, ip->name) <= 0) break;
ipp= &ip->next;
}
if (add) {
ip= alloc(sizeof(*ip));
ip->name= alloc((strlen(name) + 1) * sizeof(ip->name[0]));
strcpy(ip->name, name);
ip->next= *ipp;
*ipp= ip;
n_ignored++;
} else {
assert(ip != nil);
*ipp= ip->next;
free(ip->name);
free(ip);
n_ignored--;
}
}
int is_ignored(const char *name)
/* Is a file in the list of ignored files? */
{
struct file *ip;
int r;
ip= ignore_list[ihash(name)];
while (ip != nil) {
if ((r = strcmp(name, ip->name)) <= 0) return (r == 0);
ip= ip->next;
}
return 0;
}
#define is_ignored(name) (n_ignored > 0 && (is_ignored)(name))
time_t retired, dotretired;
enum level { TOP, DOWN };
void cleandir(enum level level, time_t retired)
{
struct file *list;
struct stat st;
time_t ret;
if (debug >= 2) fprintf(stderr, "Cleaning %s\n", path);
list= listdir();
while (list != nil) {
int didx;
ret= (level == TOP && list->name[0] == '.') ?
dotretired : retired;
/* don't rm tmp/.* too soon. */
addpath(&didx, list->name);
if (is_ignored(path)) {
if (debug >= 1) fprintf(stderr, "ignoring %s\n", path);
do_ignore(0, path);
} else
if (is_ignored(list->name)) {
if (debug >= 1) fprintf(stderr, "ignoring %s\n", path);
} else
if (lstat(path, &st) < 0) {
report(path);
} else
if (S_ISDIR(st.st_mode)) {
cleandir(DOWN, ret);
if (force || st.st_mtime < ret) {
if (debug < 3 && rmdir(path) < 0) {
if (errno != ENOTEMPTY
&& errno != EEXIST) {
report(path);
}
} else {
if (debug >= 1) {
fprintf(stderr,
"rmdir %s\n", path);
}
}
}
} else {
if (force || (st.st_atime < ret
&& st.st_mtime < ret
&& st.st_ctime < ret)
) {
if (debug < 3 && unlink(path) < 0) {
if (errno != ENOENT) {
report(path);
}
} else {
if (debug >= 1) {
fprintf(stderr,
"rm %s\n", path);
}
}
}
}
delpath(didx);
list= shorten(list);
}
}
void usage(void)
{
fprintf(stderr,
"Usage: cleantmp [-d[level]] [-i file ] ... -days|-f directory ...\n");
exit(1);
}
int main(int argc, char **argv)
{
int i;
unsigned long days;
i= 1;
while (i < argc && argv[i][0] == '-') {
char *opt= argv[i++] + 1;
if (opt[0] == '-' && opt[1] == 0) break;
if (opt[0] == 'd') {
debug= 1;
if (opt[1] != 0) debug= atoi(opt + 1);
} else
if (opt[0] == 'i') {
if (*++opt == 0) {
if (i == argc) usage();
opt= argv[i++];
}
do_ignore(1, opt);
} else
if (opt[0] == 'f' && opt[1] == 0) {
force= 1;
days= 1;
} else {
char *end;
days= strtoul(opt, &end, 10);
if (*opt == 0 || *end != 0
|| days == 0
|| ((time_t) (days * SEC_DAY)) / SEC_DAY != days
) {
fprintf(stderr,
"cleantmp: %s is not a valid number of days\n",
opt);
exit(1);
}
}
}
if (days == 0) usage();
days2time(days, &retired, &dotretired);
while (i < argc) {
int didx;
if (argv[i][0] == 0) {
fprintf(stderr, "cleantmp: empty pathname!\n");
exit(1);
}
addpath(&didx, argv[i]);
cleandir(TOP, retired);
delpath(didx);
assert(path[0] == 0);
i++;
}
exit(0);
}