JMU CS 361 Final

Everything from the PDF provided by Dr. Kirkpatrick 😋😋😋😋😋

accept

int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);

Accepts an incoming connection on a listening socket. Returns a new connected socket.

Ex: accept(server_fd, (struct sockaddr *)&cli, &len);

bind

int bind(int socket, const struct sockaddr *address, socklen_t address_len);

Assigns an IP/port to a socket.

Ex: bind(fd, (struct sockaddr *)&addr, sizeof(addr));

calloc

void* calloc(size_t num, size_t size);

Allocates zero-initialized memory.

Ex: int *a = calloc(10, sizeof(int));

close

int close(int fd);

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Closes a file descriptor or socket.

connect

int connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
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Initiates a connection to a remote socket.
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Ex: connect(fd, (struct sockaddr *)&server, sizeof(server));

dup2

int dup2(int oldfd, int newfd);

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Duplicates a file descriptor to a specific fd number. dup2(fd, STDOUT_FILENO);

execl

int execl(const char *path, const char *arg, ...);

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Executes a program.

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execl("/bin/ls", "ls", "-l", NULL);

execle

int execle(const char *path, const char *arg, ..., char * const envp[]);

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Executes a program with custom environment.

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execle("/bin/ls", "ls", NULL, envp);

execlp

int execlp(const char *file, const char *arg, ...);

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Executes using PATH search.

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execlp("ls", "ls", "-a", NULL);

execv

int execv(const char *path, char *const argv[]);

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Executes program with argv.

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execv("/bin/ls", (char *[]){"ls", "-l", NULL});

execve

int execve(const char *path, char *const argv[], char *const envp[]);

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Executes program with environment.

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execve("/bin/ls", argv, envp);

execvp

int execvp(const char *file, char *const argv[]);
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Executes using PATH.
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execvp("ls", argv);

fork

pid_t fork(void);

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Creates a new process. pid == 0 is child, < 0 failed, else parent

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pid_t pid = fork();

free

void free(void *ptr);

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Frees allocated memory.

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free(p);

fstat

int fstat(int fd, struct stat *buf);

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Gets file info from file descriptor.

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fstat(fd, &st);

getaddrinfo

int getaddrinfo(const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res);

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Hostname/IP resolution.

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getaddrinfo("localhost", "80", &hints, &res);

getenv

char *getenv(const char *name);

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Gets environment variable.

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char *p = getenv("PATH");

getpid

pidt getpid(void);

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Returns current process ID.

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pidt pid = getpid();

getppid

pidt getppid(void);

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Returns parent process ID.

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pidt p = getppid();

htonl

uint32t htonl(uint32t hostlong);

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Host to network (32-bit).

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uint32_t v = htonl(1234);

htons

uint16t htons(uint16t hostshort);

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Host to network (16-bit).

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uint16_t p = htons(80);

inet_addr

inaddrt inetaddr(const char *cp);

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String IPv4 to binary.

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ip.saddr = inet_addr("127.0.0.1");

inet_aton

int inetaton(const char *cp, struct inaddr *inp);

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Parses IPv4.

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inet_aton("1.2.3.4", &addr);

inet_ntoa

char *inetntoa(struct inaddr in);

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Binary IPv4 to string.

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printf("%s", inet_ntoa(addr));

inet_ntop

const char *inetntop(int af, const void *src, char *dst, socklent size);

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Binary IP → string.

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inetntop(AFINET, &addr, buf, sizeof(buf));

kill

int kill(pid_t pid, int sig);

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Sends signal to process.

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kill(pid, SIGTERM);

listen

int listen(int sockfd, int backlog);

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Marks socket as passive.

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listen(fd, 10);

malloc

void *malloc(size_t size);

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Allocates memory.

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int *p = malloc(sizeof(int));

memcpy

void *memcpy(void *dest, const void *src, size_t n);

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Copy memory.

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memcpy(buf2, buf1, 100);

memset

void *memset(void *s, int c, size_t n);

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Fill memory with value.

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memset(buf, 0, 256);

mkfifo

int mkfifo(const char *pathname, mode_t mode);

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Creates named pipe.

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mkfifo("pipe1", 0666);

mmap

void *mmap(void *addr, sizet length, int prot, int flags, int fd, offt offset);

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Maps file to memory.

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ptr = mmap(NULL, 4096, PROTREAD, MAPPRIVATE, fd, 0);

msync

int msync(void *addr, sizet length, int flags);

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Syncs mmap to disk.

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msync(ptr, 4096, MSSYNC);

ntohl

uint32t ntohl(uint32t netlong);

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Network → host (32-bit).

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v = ntohl(n);

hawk tuah

spit on that thang!!!

ntohs

uint16t ntohs(uint16t netshort);

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Network → host (16-bit).

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p = ntohs(n);

open

int open(const char *pathname, int flags, …);

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Opens a file.

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fd = open("file.txt", O_RDONLY);

pipe

int pipe(int pipefd[2]);

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Creates a pipe.

posix_spawn

int posix_spawn(pidt *pid, const char *path, …);

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Spawns a process.

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posix_spawn(&pid, "/bin/ls", NULL, NULL, argv, envp);

pthread_create

int pthread_create(pthread_t *thread, const pthread_attrt *attr, void (start_routine)(void *), void *arg);

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Creates thread.

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pthread_create(&t, NULL, func, NULL);

pthread_exit

void pthread_exit(void *retval);

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Ends calling thread.

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pthread_exit(NULL);

pthread_join

int pthread_join(pthread_t thread, void **retval);

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Waits for a thread.

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pthread_join(t, NULL);

pthreadmutexlock

int pthread_mutex_lock(pthreadmutext *mutex);

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Locks mutex.

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pthreadmutexlock(&m);

pthreadmutexunlock

int pthread_mutex_unlock(pthread_mutext *mutex);

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Unlocks mutex.

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pthread_mutex_unlock(&m);

read

ssizet read(int fd, void *buf, sizet count);

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Reads bytes from fd.

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read(fd, buf, 100);

realloc

void *realloc(void *ptr, size_t size);

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Resizes memory.

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p = realloc(p, 200);

recv

ssize_t recv(int sockfd, void *buf, sizet len, int flags);

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Receives data.

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recv(fd, buf, 256, 0);

Dr. Kirkpatrick’s Belly

recvfrom

ssize_t recvfrom(int sockfd, void *buf, sizet len, int flags, struct sockaddr *src, socklen_t *srclen);

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Receives UDP datagram.

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recvfrom(fd, buf, 256, 0, (struct sockaddr *)&cli, &len);

sem_init

int seminit(semt *sem, int pshared, unsigned int value);

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Initializes semaphore.

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sem_init(&sem, 0, 1);

sem_post

int sempost(semt *sem);

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Increments semaphore.

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sem_post(&sem);

sem_wait

int semwait(semt *sem);

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Decrements semaphore.

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sem_wait(&sem);

send

ssizet send(int sockfd, const void *buf, sizet len, int flags);

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Sends data.

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send(fd, "hi", 2, 0);

sendto

ssize_t sendto(int sockfd, const void *buf, sizet len, int flags, const struct sockaddr *dest, socklen_t destlen);

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Sends UDP datagram.

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sendto(fd, msg, mlen, 0, (struct sockaddr *)&addr, sizeof(addr));

sigaction

int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact);

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Installs signal handler.

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sigaction(SIGINT, &sa, NULL);

LOL!!! TROLL CARD!!!

snprintf

int snprintf(char *str, size_t size, const char *format, …);

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Formatted output (safe).

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snprintf(buf, 64, "x=%d", x);

stat

int stat(const char *path, struct stat *buf);

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Gets file metadata.

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stat("file.txt", &st);

strdup

char *strdup(const char *s);

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Duplicate string.

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char *p = strdup("hello");

strncat

char *strncat(char *dest, const char *src, size_t n);

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Append n chars.

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strncat(a, b, 5);

strncpy

char *strncpy(char *dest, const char *src, size_t n);

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Copy up to n chars.

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strncpy(buf, src, 10);

strtok

char *strtok(char *str, const char *delim);

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Tokenize string.

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char *tok = strtok(s, " ");

wait

pid_t wait(int *status);

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Waits for child.

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wait(NULL);

waitpid

pid_t waitpid(pidt pid, int *status, int options);

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Waits for specific child.

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waitpid(pid, NULL, 0);

write

ssize_t write(int fd, const void *buf, sizet count);

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Writes bytes to fd.

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write(fd, "hi", 2);