# echo przykład przykład. echo przykład

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4 # # echo przykład przykład echo przykład

5 fg jobs # sleep 10 # <Ctrl-Z> # ls... # jobs [1]+ Stopped sleep 10 # fg,,,,, #include <stdio.h> int main() printf( Hello world!\n ); vi mcedit pico jed emacs

6 # cc -o hello hello.c #./hello Hello world! # cc -Wall -o hello hello.c hello.c: In function main : hello.c:6: warning: control reaches end of non-void function int main() return 0; -Wall printf(3) # man 3 printf # export LANG=pl_PL.UTF-8 # man 2 open aplikacja funkcje biblioteczne funkcje systemowe (jądro systemu) write printf printf printf write

7 man # man 2 open # man 3 printf printf main() int char** int main(int argc, char* argv[]) int i; for(i=0; i<argc; i++) printf( argument %d: %s\n, i, argv[i]);

8 open open O_RDONLY O_WRONLY O_RDWR O_CREAT open fd = open( przyklad.txt, O_WRONLY O_CREAT, 0644); open stdin stdout stderr przykład.txt open close(fd);

9 close write(fd, Czesc, 5); write char buf[20];... n = read(fd, buf, 20); read write read read while((n=read(fd, buf, 20)) > 0) write(1, buf, n); errno int perror errno fd = open( przyklad.txt, O_RDONLY); if (fd == -1) printf( Kod: %d\n, errno); perror( Otwarcie pliku ); exit(1); errno errno.h setlocale(lc_all, pl_pl.utf-8 );

10 fd = open( przyklad.txt, O_WRONLY O_APPEND O_CREAT, 0644); fd = unlink( przyklad.txt ); ftruncate fd = open( przyklad.txt, O_WRONLY); ftruncate(fd, 0); # umask 022 # umask 077 umask lseek int lseek(int fd, int offset, int whence); offset whence SEEK_SET SEEK_CUR SEEK_END lseek(fd, -1, SEEK_END); cat # mycat a.txt b.txt c.txt cp tee # ps ax mytee wynik.log wc

11 toupper # cat plik.txt tr a-z A-Z cmp lseek flock int fd = open(...); flock(fd, LOCK_EX);... flock(fd, LOCK_UN); LOCK_EX LOCK_SH fcntl struct flock lck; int fd = open(...); lck.l_type = F_WRLCK; lck.l_start = 10; lck.l_len = 20; lck.l_whence = SEEK_SET; fcntl(fd, F_SETLKW, &lck);... lck.l_type = F_UNLCK; fcntl(fd, F_SETLKW, &lck); F_WRLCK l_type F_RDLCK #./baza dane.db w A test dane.db #./baza dane.db r A

12 test hexdump # hexdump -C dane.db

13 printf( Poczatek\n ); fork(); printf( Koniec\n ); sleep fork ps -l #./a.out & # ps -l F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD 0 R pts/2 00:00:00 bash 0 S schedu pts/2 00:00:00 a.out 0 S schedu pts/2 00:00:00 a.out 1 R pts/2 00:00:00 ps fork getpid getppid int x; x = fork(); printf( wynik fork=%d PID=%d PPID=%d\n, x, getpid(), getppid()); fork(); fork(); if (fork()==0) fork();

14 printf( Poczatek\n ); execl( /bin/ls, ls, -l, NULL); printf( Koniec\n ); ls -l printf( Poczatek\n ); if (fork()==0) /* proces potomny */ execlp( ls, ls, -l, NULL); exit(1); printf( Koniec\n ); if (fork()==0) /* proces potomny */... else /* proces macierzysty */ wait(null); printf( Koniec\n ); if (fork()==0) /* proces potomny */ exit(5); else /* proces macierzysty */ int stat; wait(&stat); printf( status=%d\n, stat>>8); sleep exec execvp execvp sort -n -k 3,3 -t: /etc/passwd

15 ps ax out.txt int fd; close(1); fd = open( out.txt, O_WRONLY O_CREAT, 0644); execlp( ps, ps, ax, NULL); dup dup2 int fd; fd = open( out.txt, O_WRONLY O_CREAT, 0644); dup2(fd, 1); # ls -l -a -i >> wynik.txt # grep xy < dane.txt > wynik1.txt 2> wynik2.txt

16 #include <stdio.h> #include <signal.h> void obsluga(int signo) printf( Odebrano sygnał %d\n, signo); int main() signal(sigint, obsluga); while(1) ; #./a.out C Odebrano sygnał 2 \ Quit kill #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <signal.h> void obsluga(int signo)

17 printf( Odebrano sygnał %d\n, signo); exit(0); int main() int pid; if ((pid=fork())==0) signal(sigint, obsluga); while(1); sleep(2); printf( Wysyłam sygnał do procesu potomnego %d\n, pid); kill(pid, 2); return 0; alarm pause pause printf( Naciśnij Ctrl-C\n ); pause(); printf( Dziękuję!\n ); sleep int x = 0;... while(x==0) ; x # cc -O2 czekaj.c -o czekaj #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <unistd.h> #include <sys/wait.h>

18 void obsluga(int signo) int s; wait(&s); printf( Status zakończenia procesu potomnego: %d\n, s>>8); int main() signal(sigchld, obsluga); if (fork()==0) sleep(3); exit(5); while(1) sleep(1); printf( Proces macierzysty\n ); waitpid

19 pipe #include <stdio.h> #include <unistd.h> int main() int fd[2]; char buf[100]; pipe(fd); write(fd[1], Hello, 6); read(fd[0], buf, 6); printf( %s\n, buf); return 0; pipe(fd); if (fork()==0) write(...); exit(0);... sleep ls tr a-z A-Z #include <stdio.h>

20 #include <unistd.h> int main() int fd[2]; pipe(fd); if (fork()==0) dup2(fd[1], 1); execlp( ls, ls, NULL); else dup2(fd[0], 0); execlp( tr, tr, a-z, A-Z, NULL); return 0; out.txt # ls tr a-z A-Z > out.txt # ls -l /tmp sort -n -k 5,5 tail -5 # hostname -f #include <stdio.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> int main() int fd; mkfifo( fifo, 0600); fd = open( fifo, O_WRONLY); write(fd, Hello, 6); close(fd); return 0;

21 ps ax tr a-z A-Z socketpair int fd[2]; if ((socketpair(pf_unix, SOCK_STREAM, 0, fd))==-1) perror( socketpair ); exit(1);

22 #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/ipc.h> #include <sys/shm.h> int main() int id; id = shmget(0x111, 1024, 0600 IPC_CREAT); if (id==-1) perror( shmget ); exit(1); printf( Blok utworzony: %d\n, id); return 0; ipcs # ipcs Shared Memory Segments key shmid owner perms bytes nattch status 0x sobaniec Semaphore Arrays key semid owner perms nsems Message Queues key msqid owner perms used-bytes messages ipcrm # ipcrm -M 0x111

23 # ipcrm -m char* ptr;... ptr = shmat(id, NULL, 0); strcpy(ptr, Ala ma kota ); char* ptr;... shmdt(ptr); id = shmget(0x111, 1024, 0);... shmctl(id, IPC_RMID, NULL);

24 #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <unistd.h> #include <sys/ipc.h> #include <sys/shm.h> #include <string.h> void obsluga(int sig) printf( sygnał w procesie %d\n, getpid()); int main() int id; char *ptr; int pid; signal(sighup, obsluga); id = shmget(0x111, 1024, 0600 IPC_CREAT); if (id==-1) perror( shmget ); exit(1); ptr = (char*)shmat(id, NULL, 0); if ((pid=fork())==0) int ppid = getppid(); sleep(1); while(1) strcpy(ptr, xxxxxx ); sleep(1); kill(ppid, 1); pause(); strcpy(ptr, oooooo ); sleep(1); kill(ppid, 1); pause(); else while(1) pause(); printf( %s\n, ptr); sleep(1); kill(pid, 1);

25 #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <unistd.h> #include <sys/ipc.h> #include <sys/shm.h> #include <string.h> int ok = 0; void obsluga(int sig) ok = 1; int main() int id; char *ptr; int pid; signal(sighup, obsluga); id = shmget(0x111, 1024, 0600 IPC_CREAT); if (id==-1) perror( shmget ); exit(1); ptr = (char*)shmat(id, NULL, 0); if ((pid=fork())==0) int ppid = getppid(); while(1) strcpy(ptr, xxxxxx ); ok = 0; kill(ppid, 1); while(!ok); strcpy(ptr, oooooo ); ok = 0; kill(ppid, 1); while(!ok); else while(1) while(!ok); printf( %s\n, ptr); ok = 0; kill(pid, 1);

26 #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <unistd.h> #include <sys/ipc.h> #include <sys/shm.h> #include <string.h> void obsluga(int sig) int main() int id; char *ptr; int pid; sigset_t mask, mask_old; signal(sighup, obsluga); sigemptyset(&mask); sigaddset(&mask, SIGHUP); sigprocmask(sig_block, &mask, &mask_old); id = shmget(0x111, 1024, 0600 IPC_CREAT); if (id==-1) perror( shmget ); exit(1); ptr = (char*)shmat(id, NULL, 0); if ((pid=fork())==0) int ppid = getppid(); while(1) strcpy(ptr, xxxxxx ); kill(ppid, 1); sigsuspend(&mask_old); strcpy(ptr, oooooo ); kill(ppid, 1); sigsuspend(&mask_old); else while(1) sigsuspend(&mask_old); printf( %s\n, ptr); kill(pid, 1);

27 #include <stdio.h> #include <stdlib.h> #include <sys/sem.h> int main() int sid; struct sembuf op; sid = semget(0x123, 1, 0600 IPC_CREAT); if (sid == -1) perror( semget ); exit(1); op.sem_num = 0; op.sem_flg = 0; /* podniesienie semafora (+1) */ op.sem_op = 1; semop(sid, &op, 1); /* opuszczenie semafora (-1) */ op.sem_op = -1; semop(sid, &op, 1); return 0; ipcs # ipcs Shared Memory Segments

28 key shmid owner perms bytes nattch status Semaphore Arrays key semid owner perms nsems 0x sobaniec Message Queues key msqid owner perms used-bytes messages ipcrm # ipcrm -S 0x123 # ipcrm -s int num;... num = semctl(sid, 0, GETVAL, 0); printf( semaphore value: %d\n, num); num = 1; semctl(sid, 0, SETVAL, num); #include <stdio.h> #include <stdlib.h> #include <sys/sem.h> int main(int argc, char* argv[]) int sid; struct sembuf op; sid = semget(0x123, 1, 0600 IPC_CREAT); if (sid == -1) perror( semget ); exit(1); printf( przed: %d\n, semctl(sid, 0, GETVAL, NULL)); op.sem_num = 0; op.sem_flg = 0; op.sem_op = atoi(argv[1]); semop(sid, &op, 1); printf( po: %d\n, semctl(sid, 0, GETVAL, NULL)); return 0; #include <stdio.h>

29 #include <stdlib.h> #include <unistd.h> #include <sys/sem.h> int main(int argc, char* argv[]) int sid; int num; struct sembuf op; sid = semget(0x123, 1, 0600 IPC_CREAT); if (sid == -1) perror( semget ); exit(1); if (argc>1) printf( Inicjacja semafora...\n\n ); num = 1; semctl(sid, 0, SETVAL, num); op.sem_num = 0; op.sem_flg = 0; while(1) printf( Wchodzę do sekcji krytycznej...\n ); op.sem_op = -1; semop(sid, &op, 1); printf( Jestem w sekcji krytycznej...\n ); sleep(5); op.sem_op = 1; semop(sid, &op, 1); printf( Wyszedłem z sekcji krytycznej...\n ); sleep(1); return 0;

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31 msgget(2) mid = msgget(0x123, 0600 IPC_CREAT); ipcs long typedef struct long type; char text[1024]; MSG; msgsnd(2) MSG msg;... msgsnd(mid, &msg, strlen(msg.text)+1, 0); ipcs msgrcv(2) MSG msg;... msgrcv(mid, &msg, 1024, 0, 0); msgrcv long

32 msgrcv IPC_NOWAIT msgctl msgctl(mid, IPC_RMID, NULL); ipcrm

33 #include <stdio.h> #include <unistd.h> #include <pthread.h> void* worker(void* info) int i; for(i=0; i<10; i++) sleep(1); printf( thread\n ); return NULL; int main() pthread_t th; int i; pthread_create(&th, NULL, worker, NULL); for(i=0; i<10; i++) sleep(1); printf( main program\n ); pthread_join(th, NULL); return 0; # cc -o thtest thtest.c -lpthread # ps x # ps -L x

34 # ps -T x int d = 1; pthread_create(&th, NULL, worker, &d); #include <stdio.h> #include <unistd.h> #include <pthread.h> pthread_mutex_t mx; void* worker(void* info) int i; int tid = *(int*)info; for(i=0; i<10; i++) printf( Thread %d is entering critical section...\n, tid); pthread_mutex_lock(&mx); printf( Thread %d is in critical section...\n, tid); sleep(5); pthread_mutex_unlock(&mx); printf( Thread %d is leaving critical section...\n, tid); sleep(2); return NULL; int main() pthread_t th1, th2, th3; int w1=1, w2=2, w3=3; pthread_mutex_init(&mx, NULL); pthread_create(&th1, NULL, worker, &w1); pthread_create(&th2, NULL, worker, &w2); pthread_create(&th3, NULL, worker, &w3); pthread_join(th1, NULL); pthread_join(th2, NULL); pthread_join(th3, NULL); return 0; pthread_join(3)

35 int pthread_join(pthread_t th, void **retval); wait retval void pthread_exit(void *retval); retval pthread_join pthread_cancel int pthread_cancel(pthread_t thread); int pthread_setcancelstate(int state, int *oldstate); int pthread_detach(pthread_t th); pthread_join signal int pthread_kill(pthread_t thread, int signo); int pthread_sigmask(int how, const sigset_t *newmask, sigset_t *oldmask); newmask unsigned long int sigemptyset(sigset_t *set); int sigfillset(sigset_t *set); int sigaddset(sigset_t *set, int signum); int sigdelset(sigset_t *set, int signum); int sigismember(const sigset_t *set, int signum); pthread_sigmask int sigwait(const sigset_t *set, int *sig);

36 int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *mutexattr); pthread_mutex_t m;... pthread_mutex_init(&m, NULL); pthread_mutex_lock() pthread_mutex_trylock() EBUSY pthread_mutex_unlock() pthread_mutex_destroy() pthread_mutex_t int pthread_cond_t c;... pthread_cond_init(&c, NULL); int pthread_cond_signal(pthread_cond_t *cond); int pthread_cond_broadcast(pthread_cond_t *cond); pthread_cond_signal() pthread_cond_broadcast()

37 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex); int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime); pthread_cond_wait() pthread_cond_timedwait() pthread_cond_t c; pthread_mutex_t m;... pthread_mutex_lock(&m); /* zajęcie zamka */ pthread_cond_wait(&c, &m); /* oczekiwanie na zmiennej warunkowej */ pthread_mutex_unlock(&m); /* zwolnienie zamka */ pthread_cond_signal(&c); /* sygnalizacja zmiennej warunkowej */ pthread_mutex_lock(&m); pthread_cond_signal(&c); pthread_mutex_unlock(&m); int pthread_cond_signal() pthread_cond_broadcast() bariera()

38 MAP_PRIVATE MAP_SHARED MAP_PRIVATE MAP_SHARED exec() fork() MAP_PRIVATE MAP_SHARED /dev/zero

39 MAP_PRIVATE malloc() /proc/ PID/maps mmap(2) void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset); MAP_FAILED struct stat sb; int fd = open( a.txt, O_RDWR); fstat(fd, &sb); void *ptr = mmap(null, sb.st_size, PROT_READ PROT_WRITE, MAP_SHARED, fd, 0); if (ptr == MAP_FAILED) perror( mmap ); ftruncate(2) fallocate(2) ftruncate() fallocate() fd = open( dane.txt, O_CREAT O_RDWR); ftruncate(fd, 0); fallocate(fd, 0, 0, 4096); munmap(2) int length = 4096; void *ptr = mmap(null, length, PROT_READ, MAP_SHARED, fd, 0);... munmap(ptr, length); msync(2) msync(ptr, length, MS_SYNC); msync(ptr, length, MS_ASYNC); fdatasync(fd); // or fsync(fd) fdatasync(2) msync(ptr, length, MS_INVALIDATE);

40 mprotect(2) mlock(2) mlockall(2) madvice(2) PROT_NONE PROT_READ PROT_WRITE

41 ls rm ipcs ipcrm open(2) int fd = shm_open( /mymem, O_CREAT O_RDWR, 0600); /nazwa /dev/shm open(2) O_CREAT O_EXCL O_TRUNC ftruncate(2) ftruncate(fd, 4096); /dev/shm shm_unlink(2)

42 shm_unlink( /mymem ); sem_init() sem_wait() sem_trywait() sem_post() sem_getvalue() sem_destroy() sem_init() # gcc sem-test.c -lpthread sem_t *s; s = mmap(null, sizeof(sem_t), PROT_READ PROT_WRITE, MAP_SHARED MAP_ANONYMOUS, -1, 0); if (s == MAP_FAILED) perror( mmap ); sem_init(s, 1, 1); sem_wait(s); sem_t *s = sem_open( /mysem, O_CREAT, 0600, 1); if (s==sem_failed) perror( sem_open );

43 #include <stdio.h> #include <unistd.h> #include <pthread.h> #include <semaphore.h> sem_t s; void* work(void* arg) int id = pthread_self(); int i; for(i=0; i<10; i++) printf( [%d] Czekam...\n, id); sem_wait(&s); printf( [%d] Sekcja krytyczna...\n, id); sleep(1); printf( [%d] Wyjście...\n, id); sem_post(&s); usleep(100000); return NULL; int main() pthread_t th1, th2; sem_init(&s, 0, 1); pthread_create(&th1, NULL, work, NULL); pthread_create(&th2, NULL, work, NULL); pthread_join(th1, NULL); pthread_join(th2, NULL); return 0;

44 sem_t /dev/shm sem.mysem sem_close(s); sem_unlink( /mysem ); mq_open(2) mq_attr mq_send(2) mq_receive(2) NULL unlink() mq_unlink( /kolejka );

45 #include <stdio.h> #include <fcntl.h> #include <string.h> #include <mqueue.h> int main(int argc, char *argv[]) mqd_t mq; struct mq_attr attr; attr.mq_flags = 0; attr.mq_maxmsg = 10; attr.mq_msgsize = 1024; mq = mq_open(argv[1], O_RDWR O_CREAT, 0600, &attr); if (mq==-1) perror( mq_open ); if (argc>2) mq_send(mq, argv[2], strlen(argv[2])+1, atoi(argv[3])); else char str[1024]; int prio; mq_receive(mq, str, 1024, &prio); printf( %d: %s\n, prio, str);

46 # ls /dev/mqueue kolejka # cat /dev/mqueue/kolejka QSIZE:55 NOTIFY:0 SIGNO:0 NOTIFY_PID:0 # rm /dev/mqueue/kolejka mq_receive() struct sigevent ev; ev.sigev_notify = SIGEV_SIGNAL; ev.sigev_signo = SIGUSR1; mq_notify(mq, &ev); void handler(union sigval sv) mqd_t mq = *((mqd_t*)sv.sival_ptr); struct sigevent ev; mqd_t mq = mq_open(...); ev.sigev_notify = SIGEV_THREAD; ev.sigev_notify_function = handler; ev.sigev_notify_attributes = NULL; ev.sigev_value.sival_ptr = &mq; mq_notify(mq, &ev); mqd_t

47 # cc -o prg modul_1.c modul_2.c prg.c modul_.c modul_.c prg.c main # cc -c modul_1.c # cc -c modul_2.c # cc -o prg modul_1.o modul_2.o prg.c.o.a tar modul_.c modul_.c # cc -c modul_1.c # cc -c modul_2.c # ar rv libmodul.a modul_1.o modul_2.o # cc -o prg prg.c libmodul.a

48 # cc -shared -o libmodul.so modul_1.c modul_2.c # cc -o prg prg.c -lmodul -L. -L modul ldd # ldd prg linux-gate.so.1 => (0xffffe000) libc.so.6 => /lib/libc.so.6 (0x ) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x ) modul.so =>./modul.so (0x ) #include <stdio.h> #include <stdlib.h> #include <dlfcn.h> int main() void* handle = dlopen( libhello.so, RTLD_LAZY); void (*fun)(); if (handle == NULL) printf( %s\n, dlerror()); exit(1); else fun = dlsym(handle, fun ); (*fun)(); dlclose(handle); return 0; #include <stdio.h> void fun() printf( Hello world\n ); dlopen(3)

49 rand(3) RAND_MAX srand(3) [, ] float f = rand()/(rand_max+1.0); x int x; srand(getpid()); x = *(rand()/(RAND_MAX+1.0)); getpid #include <stdio.h> #include <readline/readline.h> int main() char* line; while ((line=readline( pisz> ))!=NULL) if (*line)

50 printf( %s\n, line); # gcc -o readline-test -lreadline readline-test.c line = readline( > ); add_history(line);

51 # ls -l > out.txt # grep abc < dane.txt # sort < dane.txt > out.txt exit fg bg jobs isatty() #!/home/student/mysh ls -l ps ax > out.txt

52 # ps ax head # ps ax head # ls -l tr a-z A-Z sort -n -k 5,5 # cat < dane.txt tr abc XYZ sort > out.txt echo $1 $2 #!/home/student/mysh ls -l $1 tr -s \t cut -f $2 > X=10 > echo $X 10 > zmienna= Ala ma kota > echo $zmienna Ala ma kota > unset zmienna > echo $zmienna > setenv() = proces.txt

53 proces.txt ps -ax iostat netstat -tn log.txt numbers.txt

54 gcc cc -Wall error: x undeclared (first use in this function) x warning: implicit declaration of function sleep sleep sleep sleep(3) unistd.h #include <unistd.h> warning: no newline at end of file mcedit

55

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57 add_history dlopen exec perror printf pthread_join rand readline sleep srand toupper alarm close dup2 dup fallocate fcntl fdatasync flock fork ftruncate getpid getppid lseek madvice mlockall mlock mmap mprotect mq_open mq_receive mq_send msgget msgrcv msgsnd msync munmap open pause pipe read sem_destroy sem_getvalue sem_init sem_open sem_post sem_trywait sem_wait shm_open shm_unlink signal socketpair umask waitpid write