, , -
- "" !
x
S_IEXEC. . , /
, (chdir),
( namei() ): -
; I-
d_ino; I-
. "" -
. -
(.. ls);
"" -
( , , , stat, chdir).
.. "" read, "" -
namei. "" " ";
- I-nod .
t sticky bit
S_ISVTX - ,
: , , -
. . .
: :
chmod o-w,+t
BSD , ,
. ,
: opendir, closedir, readdir. ,
ls .
. , 1992-95 - 192 - UNIX
#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
int listdir(char *dirname){
register struct dirent *dirbuf;
DIR *fddir;
ino_t dot_ino = 0, dotdot_ino = 0;
if((fddir = opendir (dirname)) == NULL){
fprintf(stderr, "Can't read %s\n", dirname);
return 1;
}
/* */
while ((dirbuf = readdir (fddir)) != NULL ) {
if (dirbuf->d_ino == 0) continue;
if (strcmp (dirbuf->d_name, "." ) == 0){
dot_ino = dirbuf->d_ino;
continue;
} else if(strcmp (dirbuf->d_name, "..") == 0){
dotdot_ino = dirbuf->d_ino;
continue;
} else printf("%s\n", dirbuf->d_name);
}
closedir (fddir);
if(dot_ino == 0) printf(" : \".\"\n");
if(dotdot_ino == 0) printf(" : \"..\"\n");
if(dot_ino && dot_ino == dotdot_ino) printf(" \n");
return 0;
}
int main(int ac, char *av[]){
int i;
if(ac > 1) for(i=1; i < ac; i++) listdir(av[i]);
else listdir(".");
return 0;
}
, '\0' d_name, -
readdir().
6.1.4. , argv.
stat, (/). -
.
( , "." "..") -
rmdir(_);
( - errno EEXIST);
( )
unlink(_);
,
, , " ?".
6.1.5.
. U42 (BSD 4.2).
. , 1992-95 - 193 - UNIX
/*#!/bin/cc -DFIND -DU42 -DMATCHONLY treemk.c match.c -o tree -lx
* ( & ).
* :
* BSD-4.2 BSD-4.3 -DU42
* XENIX ..
* XENIX -lx -DU42
* -DFIND
* -DRM_REC
* _
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h> /* MAXPATHLEN */
#if defined(M_XENIX) && defined(U42)
# include <sys/ndir.h> /* XENIX + U42 */
#else
# include <dirent.h>
# define stat(f,s) lstat(f,s) /* */
# define d_namlen d_reclen
#endif
/* : */
#define isdir(st) ((st.st_mode & S_IFMT) == S_IFDIR)
struct stat st; /* stat() */
char buf[MAXPATHLEN+1]; /* */
#define FAILURE (-1) /* */
#define SUCCESS 1 /* */
#define WARNING 0 /* */
/* : */
#ifndef ERR_CANT_READ
# define ERR_CANT_READ(name) \
fprintf( stderr, "\t \"%s\"\n", name), WARNING
# define ERR_NAME_TOO_LONG() \
fprintf( stderr, "\t \n" ), WARNING
#endif
/* . */
extern char *strrchr(char *, char);
int directory (char *name, int level,
int (*enter)(char *full, int level, struct stat *st),
int (*leave)(char *full, int level),
int (*touch)(char *full, int level, struct stat *st));
/* - enter, leave, touch
* (-1) ,
* >= 0 . */
. , 1992-95 - 194 - UNIX
/* rootdir */
int walktree (
char *rootdir, /* */
int (*enter)(char *full, int level, struct stat *st),
int (*leave)(char *full, int level),
int (*touch)(char *full, int level, struct stat *st)
){
/* */
if( stat(rootdir, &st) < 0 || !isdir(st)){
fprintf( stderr, "\t \"%s\"\n", rootdir );
return FAILURE; /* */
}
strcpy (buf, rootdir);
return act (buf, 0, enter, leave, touch);
}
/* name.
*/
int act (char *name, int level,
int (*enter)(char *full, int level, struct stat *st),
int (*leave)(char *full, int level),
int (*touch)(char *full, int level, struct stat *st))
{
if (stat (name, &st) < 0)
return WARNING; /* , */
if(isdir(st)){ /* */
if(enter)
if( enter(name, level, &st) == FAILURE ) return FAILURE;
return directory (name, level+1, enter, leave, touch);
} else { /* */
if(touch) return touch (name, level, &st);
else return SUCCESS;
}
}
. , 1992-95 - 195 - UNIX
/* : */
int directory (char *name, int level,
int (*enter)(char *full, int level, struct stat *st),
int (*leave)(char *full, int level),
int (*touch)(char *full, int level, struct stat *st))
{
#ifndef U42
struct direct dirbuf;
int fd;
#else
register struct dirent *dirbuf;
DIR *fd;
extern DIR *opendir();
#endif
char *nbp, *tail, *nep;
int i, retcode = SUCCESS;
#ifndef U42
if ((fd = open (name, 0)) < 0) {
#else
if ((fd = opendir (name)) == NULL) {
#endif
return ERR_CANT_READ(name);
}
tail = nbp = name + strlen (name); /* \0 */
if( strcmp( name, "/" )) /* "/" */
*nbp++ = '/';
*nbp = '\0';
#ifndef U42
if (nbp + DIRSIZ + 2 >= name + MAXPATHLEN) {
*tail = '\0';
return ERR_NAME_TOO_LONG();
}
#endif
#ifndef U42
while (read(fd, (char *) &dirbuf, sizeof(dirbuf)) == sizeof(dirbuf)){
if (dirbuf.d_ino == 0) /* */
continue;
if (strcmp (dirbuf.d_name, "." ) == 0 ||
strcmp (dirbuf.d_name, "..") == 0) /* */
continue;
for (i = 0, nep = nbp; i < DIRSIZ; i++)
*nep++ = dirbuf.d_name[i];
# else /*U42*/
while ((dirbuf = readdir (fd)) != NULL ) {
if (dirbuf->d_ino == 0)
continue;
if (strcmp (dirbuf->d_name, "." ) == 0 ||
strcmp (dirbuf->d_name, "..") == 0)
continue;
for (i = 0, nep = nbp; i < dirbuf->d_namlen ; i++)
*nep++ = dirbuf->d_name[i];
#endif /*U42*/
*nep = '\0';
if( act(name, level, enter, leave, touch) == FAILURE) {
retcode = FAILURE; break; }
}
. , 1992-95 - 196 - UNIX
#ifndef U42
close (fd);
#else
closedir(fd);
#endif
*tail = '\0'; /* name */
if(retcode != FAILURE && leave)
if( leave(name, level) == FAILURE) retcode = FAILURE;
return retcode;
}
/* -------------------------------------------------------------- */
/* Disk Usage -- , */
/* -------------------------------------------------------------- */
/* */
#define KB(s) (((s)/1024L) + ((s)%1024L ? 1L:0L))
/* #define KB(s) (((s) + 1024L - 1) / 1024L) */
long size; /* */
long nfiles; /* */
long ndirs; /* */
#define WARNING_LIMIT 150L /* */
static int du_touch (char *name, int level, struct stat *st){
long sz;
size += (sz = KB(st->st_size)); /* . */
nfiles++;
#ifndef TREEONLY
if( sz >= WARNING_LIMIT )
fprintf(stderr,"\t! \"%s\" : %ld .\n",
name, sz);
#endif /*TREEONLY*/
return SUCCESS;
}
static int du_enter (char *name, int level, struct stat *st){
#ifndef TREEONLY
fprintf( stderr, " \"%s\"\n", name );
#endif
size += KB(st->st_size); /* . */
nfiles++; ++ndirs; return SUCCESS;
}
long du (char *name){
size = nfiles = ndirs = 0L;
walktree(name, du_enter, NULL, du_touch );
return size;
}
. , 1992-95 - 197 - UNIX
/* -------------------------------------------------------------- */
/* */
/* -------------------------------------------------------------- */
int deleted; /* */
static int recrm_dir (char *name, int level){
if( rmdir(name) >= 0){ deleted++; return SUCCESS; }
fprintf(stderr, " rmdir '%s'\n", name); return WARNING;
}
static int recrm_file(char *name, int level, struct stat *st){
if( unlink(name) >= 0){ deleted++; return SUCCESS; }
fprintf(stderr, " rm '%s'\n", name); return WARNING;
}
int recrmdir(char *name){
int ok_code; deleted = 0;
ok_code = walktree(name, NULL, recrm_dir, recrm_file);
printf(" %d %s\n", deleted, name);
return ok_code;
}
/* -------------------------------------------------------------- */
/* ( ) */
/* -------------------------------------------------------------- */
char *find_PATTERN;
static int find_check(char *fullname, int level, struct stat *st){
char *basename = strrchr(fullname, '/');
if(basename) basename++;
else basename = fullname;
if( match(basename, find_PATTERN))
printf("Level#%02d %s\n", level, fullname);
if( !strcmp( basename, "core")){
printf(" %s, .\n", fullname);
return FAILURE;
}
return SUCCESS;
}
void find (char *root, char *pattern){
find_PATTERN = pattern;
walktree(root, find_check, NULL, find_check);
}
. , 1992-95 - 198 - UNIX
/* -------------------------------------------------------------- */
#ifndef TREEONLY
void main(int argc, char *argv[]){
#ifdef FIND
if(argc != 3){ fprintf(stderr, "Arg count\n"); exit(1); }
find(argv[1], argv[2]);
#else
# ifdef RM_REC
for(argv++; *argv; argv++)
recrmdir(*argv);
# else
du( argc == 1 ? "." : argv[1] );
printf( "%ld %ld .\n", size, nfiles );
printf( "%ld .\n", ndirs );
# endif
#endif
exit(0);
}
#endif /*TREEONLY*/
6.1.6. ,
. -
mkdir(_, _);
6.1.7. , , -
, , . ,
. UNIX
rm -r ___
6.1.8. , find,
:
- , ( -
match() " ");
- : S_IFREG,
(st.st_mode & 0111) != 0
, stat .
6.2. UNIX.
6.2.1. , , , , ,
, 00 00 00 1
1970 . : long ( time_t).
, -
"" , long ,
, , - , - ,
...; -
. UNIX
;
#include <sys/types.h>
#include <time.h>
time_t t = time(NULL); /* time(&t); */
struct tm *tm = localtime( &t );
. , 1992-95 - 199 - UNIX
, int- :
tm_year ( 1900)
tm_yday 0..365
tm_mon 0..11 (0 - )
tm_mday 1..31
tm_wday 0..6 (0 - )
tm_hour 0..23
tm_min 0..59
tm_sec 0..59
,
:
char *months[] = { "", "", ..., "" };
printf( "%s\n", months[ tm->tm_mon ] );
.
stime(&t);
6.2.2. :: --.
time() localtime().
ctime(), :
/* Mon Mar 25 18:56:36 1991 */
#include <stdio.h>
#include <time.h>
main(){ /* date */
time_t t = time(NULL);
char *s = ctime(&t);
printf("%s", s);
}
, s '\n'.
6.2.3. stat, stat(),
time_t st_ctime, st_mtime st_atime -
I- ,
.
- st_ctime ( -
) creat, chmod, chown, link, unlink, mknod,
utime|-, write (.. );
;
- st_mtime - write, creat, mknod, utime;
();
- st_atime - read, creat, mknod, utime;
().
typeOf(), .
____________________
|-
.
utime(ߔ, NULL);
make - touch.
.
. , 1992-95 - 200 - UNIX
6.2.4. ls -tm, -
, st_mtime,
.
stat; , -
.
6.2.5. ,
(st_size).
6.2.6. ls -l, -
rwxrw-r--. stat
stat( ߔ, &st);
= st.st_mode & 0777;
chmod(_, _);
,
0777 | S_ISUID | S_ISGID | S_ISVTX
( <sys/stat.h>). (. typeOf) . -
.
I- : d_ino st_ino
stat.
6.2.7. , 2 - -
:
#include <sys/types.h>
#include <sys/stat.h>
extern char *ctime();
main(){
time_t last; struct stat st;
for( stat(".", &st), last=st.st_mtime; ; sleep(2)){
stat(".", &st);
if(last != st.st_mtime){
last = st.st_mtime;
printf(" - : %s",
ctime(&last));
}
}
}
, () (
,
- ).
6.2.8. , ,
- , .
st_atime, st_mtime stat() < 0 . -
.
6.2.9. UNIX- ( )
. ""
: ;
, ; - -
, .
. , 1992-95 - 201 - UNIX
, , (
). :
sleep alarm ( , ).
#include <sys/types.h>
#include <signal.h>
#include <sys/time.h>
void do_nothing() {}
/* usec () */
void usleep(unsigned int usec) {
struct itimerval new, old;
/* struct itimerval :
struct timeval it_interval;
struct timeval it_value;
struct timeval :
long tv_sec; --
long tv_usec; --
*/
struct sigaction new_vec, old_vec;
if (usec == 0) return;
/* tv_sec .
tv_usec .
it_value - ,
"",
SIGALRM.
, , .
it_interval - ,
""
( ).
, ,
"".
*/
new.it_interval.tv_sec = 0;
new.it_interval.tv_usec = 0;
new.it_value.tv_sec = usec / 1000000;
new.it_value.tv_usec = usec % 1000000;
. , 1992-95 - 202 - UNIX
/* SIGALRM old_vec,
do_nothing()
*/
new_vec.sa_handler = do_nothing;
sigemptyset(&new_vec.sa_mask);
new_vec.sa_flags = 0;
sighold(SIGALRM);
sigaction(SIGALRM, &new_vec, &old_vec);
/* new, .
* old.
* &old NULL - .
*/
setitimer(ITIMER_REAL, &new, &old);
/* SIGALRM */
sigpause(SIGALRM);
/* SIGALRM */
sigaction(SIGALRM, &old_vec, (struct sigaction *) 0);
sigrelse(SIGALRM);
/* */
setitimer(ITIMER_REAL, &old, (struct itimerval *) 0);
}
6.2.10. - ,
( ).
gettimeofday
#include <time.h>
void main(){
struct timeval timenow;
gettimeofday(&timenow, NULL);
printf("%u sec, %u msec\n",
timenow.tv_sec,
timenow.tv_usec
);
printf("%s", ctime(&timenow.tv_sec));
exit(0);
}
tv_sec , 1 1970
; time.
tv_usec (
1000000).
6.2.11. , fork() exit().
: ( -
) (
). , ,
times(). , ,
( fork).
. , 1992-95 - 203 - UNIX
struct tms {
clock_t tms_utime;
clock_t tms_stime;
clock_t tms_cutime;
clock_t tms_cstime;
};
#include <sys/times.h>
struct tms time_buf;
clock_t real_time = times(&time_buf);
"" - .
( Solaris):
#include <unistd.h>
clock_t HZ = sysconf(_SC_CLK_TCK);
, ,
60 (60 - ). 100.
:
tms_utime
, .
tms_stime
, .
tms_cutime
, :
tms_utime tms_cutime ( -
).
tms_cstime
, :
tms_stime tms_cstime ( ).
real_time
, .
.
:
#include <stdio.h>
#include <unistd.h> /* _SC_CLK_TCK */
#include <signal.h> /* SIGALRM */
#include <sys/time.h> /* */
#include <sys/times.h> /* struct tms */
struct tms tms_stop, tms_start;
clock_t real_stop, real_start;
clock_t HZ; /* ticks */
. , 1992-95 - 204 - UNIX
/* */
void hello(void){
real_start = times(&tms_start);
}
/* */
void bye(int n){
real_stop = times(&tms_stop);
#ifdef CRONO
/* */
tms_stop.tms_utime -= tms_start.tms_utime;
tms_stop.tms_stime -= tms_start.tms_stime;
#endif
/* */
printf("User time = %g seconds [%lu ticks]\n",
tms_stop.tms_utime / (double)HZ, tms_stop.tms_utime);
printf("System time = %g seconds [%lu ticks]\n",
tms_stop.tms_stime / (double)HZ, tms_stop.tms_stime);
printf("Children user time = %g seconds [%lu ticks]\n",
tms_stop.tms_cutime / (double)HZ, tms_stop.tms_cutime);
printf("Children system time = %g seconds [%lu ticks]\n",
tms_stop.tms_cstime / (double)HZ, tms_stop.tms_cstime);
printf("Real time = %g seconds [%lu ticks]\n",
(real_stop - real_start) / (double)HZ, real_stop - real_start);
exit(n);
}
/* SIGALRM - */
void onalarm(int nsig){
printf(" #%d ================\n", getpid());
bye(0);
}
/* */
void dochild(int n){
hello();
printf(" #%d ================\n", getpid());
signal(SIGALRM, onalarm);
/* SIGALRM 1 + n*3 */
alarm(1 + n*3);
for(;;){} /* user mode */
}
. , 1992-95 - 205 - UNIX
#define NCHLD 4
int main(int ac, char *av[]){
int i;
/* */
HZ = sysconf(_SC_CLK_TCK);
setbuf(stdout, NULL);
hello();
for(i=0; i < NCHLD; i++)
if(fork() == 0)
dochild(i);
while(wait(NULL) > 0);
printf(" MAIN =================\n");
bye(0);
return 0;
}
:
#3883 ================
#3884 ================
#3885 ================
#3886 ================
#3883 ================
User time = 0.72 seconds [72 ticks]
System time = 0.01 seconds [1 ticks]
Children user time = 0 seconds [0 ticks]
Children system time = 0 seconds [0 ticks]
Real time = 1.01 seconds [101 ticks]
#3884 ================
User time = 1.88 seconds [188 ticks]
System time = 0.01 seconds [1 ticks]
Children user time = 0 seconds [0 ticks]
Children system time = 0 seconds [0 ticks]
Real time = 4.09 seconds [409 ticks]
#3885 ================
User time = 4.41 seconds [441 ticks]
System time = 0.01 seconds [1 ticks]
Children user time = 0 seconds [0 ticks]
Children system time = 0 seconds [0 ticks]
Real time = 7.01 seconds [701 ticks]
#3886 ================
User time = 8.9 seconds [890 ticks]
System time = 0 seconds [0 ticks]
Children user time = 0 seconds [0 ticks]
Children system time = 0 seconds [0 ticks]
Real time = 10.01 seconds [1001 ticks]
MAIN =================
User time = 0.01 seconds [1 ticks]
System time = 0.04 seconds [4 ticks]
Children user time = 15.91 seconds [1591 ticks]
Children system time = 0.03 seconds [3 ticks]
Real time = 10.41 seconds [1041 ticks]
, 72+188+441+890=1591 ( tms_cutime main).
6.2.12. : . :
timer ls -l
. , 1992-95 - 206 - UNIX
/* */
#include <stdio.h>
#include <unistd.h>
#include <sys/times.h>
extern errno;
typedef struct _timeStamp {
clock_t real_time;
clock_t cpu_time;
clock_t child_time;
clock_t child_sys, child_user;
} TimeStamp;
TimeStamp TIME(){
struct tms tms;
TimeStamp st;
st.real_time = times(&tms);
st.cpu_time = tms.tms_utime +
tms.tms_stime +
tms.tms_cutime +
tms.tms_cstime;
st.child_time = tms.tms_cutime +
tms.tms_cstime;
st.child_sys = tms.tms_cstime;
st.child_user = tms.tms_cutime;
return st;
}
void PRTIME(TimeStamp start, TimeStamp stop){
clock_t HZ = sysconf(_SC_CLK_TCK);
clock_t real_time = stop.real_time - start.real_time;
clock_t cpu_time = stop.cpu_time - start.cpu_time;
clock_t child_time = stop.child_time - start.child_time;
printf("%g real, %g cpu, %g child (%g user, %g sys), %ld%%\n",
real_time / (double)HZ,
cpu_time / (double)HZ,
child_time / (double)HZ,
stop.child_user / (double)HZ,
stop.child_sys / (double)HZ,
(child_time * 100L) / (real_time ? real_time : 1)
);
}
. , 1992-95 - 207 - UNIX
TimeStamp start, stop;
int main(int ac, char *av[]){
char *prog = *av++;
if(*av == NULL){
fprintf(stderr, "Usage: %s command [args...]\n", prog);
return(1);
}
start = TIME();
if(fork() == 0){
execvp(av[0], av);
perror(av[0]);
exit(errno);
}
while(wait(NULL) > 0);
stop = TIME();
PRTIME(start, stop);
return(0);
}
6.3. .
6.3.1. ustat() -
, ( - ):
#include <sys/types.h>
#include <sys/stat.h>
#include <ustat.h>
struct stat st; struct ustat ust;
void main(int ac, char *av[]){
char *file = (ac==1 ? "." : av[1]);
if( stat(file, &st) < 0) exit(1);
ustat(st.st_dev, &ust);
printf(" %*.*s\n"
"%ld (%ld )\n"
"%d I-\n",
sizeof ust.f_fname, sizeof ust.f_fname,
ust.f_fname, /* () */
ust.f_tfree, /* 512 */
(ust.f_tfree * 512L) / 1024,
ust.f_tinode );
}
printf: , -
, ANSI C :
char s[] = "This is" " a line " "of words";
char s[] = "This is a line of words";
6.3.2. , , statvfs - -
. :
.
. , 1992-95 - 208 - UNIX
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <fcntl.h> /* O_RDONLY */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/param.h> /* MAXPATHLEN */
char *progname; /* */
void error(char *fmt, ...){
va_list args;
va_start(args, fmt);
fprintf(stderr, "%s: ", progname);
vfprintf(stderr, fmt, args);
fputc('\n', stderr);
va_end(args);
}
int copyFile(char *to, char *from){ /* , */
char newname[MAXPATHLEN+1];
char answer[20];
struct stat stf, stt;
int fdin, fdout;
int n, code = 0;
char iobuf[64 * 1024];
char *dirname = NULL, *s;
if((fdin = open(from, O_RDONLY)) < 0){
error("Cannot read %s", from);
return (-1);
}
fstat(fdin, &stf);
if((stf.st_mode & S_IFMT) == S_IFDIR){
close(fdin);
error("%s is a directory", from);
return (-2);
}
. , 1992-95 - 209 - UNIX
if(stat(to, &stt) >= 0){
/* */
if((stt.st_mode & S_IFMT) == S_IFDIR){
/* */
/* from */
if((s = strrchr(from, '/')) && s[1])
s++;
else s = from;
dirname = to;
/* - */
sprintf(newname, "%s/%s", to, s);
to = newname;
if(stat(to, &stt) < 0)
goto not_exist;
}
if(stt.st_dev == stf.st_dev && stt.st_ino == stf.st_ino){
error("%s: cannot copy file to itself", from);
return (-3);
}
switch(stt.st_mode & S_IFMT){
case S_IFBLK:
case S_IFCHR:
case S_IFIFO:
break;
default:
printf("%s already exists, overwrite ? ", to);
fflush(stdout);
*answer = '\0';
gets(answer);
if(*answer != 'y'){ /* NO */
close(fdin);
return (-4);
}
break;
}
}
. , 1992-95 - 210 - UNIX
not_exist:
printf("COPY %s TO %s\n", from, to);