CSCI 347 Test 2 Review: Files and Directories

Study Notes

A UNIX file system consists of disk partitions
File types and directory entries are stored as (name, inode-number) pairs
Links can be hard (inode: data stored and access to file data via direct and indirect blocks) or symbolic
Ownership of a file can be viewed using stat, fstat, and lstat commands, with permissions for user/group/other
Set UID and Set GID bits can be set, and access control can be modified using umask, chmod, and fchmod commands
Files can be managed using chown, fchown, link, unlink, rename, and utimes commands
Directories can be managed using mkdir, rmdir, chdir, and fchdir commands
File descriptors can be manipulated using opendir, closedir, readdir, telldir, seekdir, and rewinddir commands

Standard input, output, and error streams (stdin, stdout, stderr) can be buffered, line-buffered, or unbuffered
Files can be opened using fopen, freopen, and fdopen commands
Buffering modes can be set using setbuf and setvbuf commands
File input/output can be performed using fgetc, ferror, feof, clearerr, and ungetc commands
Formatted input/output can be performed using fgets, fputs, and printf commands
Binary input/output can be performed using fread, fwrite, ftell, fseek, fgetpos, and fsetpos commands

/etc/passwd and /etc/group files store user and group information
User and group information can be retrieved using getpwuid, getpwnam, getpwent, setpwent, and endpwent commands
Supplementary Group IDs can be used to add groups to a user
/etc directory stores system information
uname(1) and uname(3) commands provide system information
Time-related functions include time, ctime, strftime, gettimeofday, and others
Time zone issues can be handled using certain functions

Process ID (pid) and group ID (gid) can be used to manage processes
fork function creates a new process, and exit function terminates a process
wait and waitpid system calls can be used to wait for a process to terminate
WIFEXITED() and WEXITSTATUS() macros provide exit status information
Zombie processes can be terminated using wait, waitpid, wait3, and wait4 commands

Pipes enable interprocess communication
Kernel pipe, pipe(2) system call creates a pipe
Pipes have read and write ends
Termination conditions include EOF on read and SIGPIPE on write
One-way communication can be achieved from child to parent, or parent to child using pipes
popen(3) and pclose(3) commands can be used to create and manage pipes
micro shell concepts include exit values, expansion, environment variables, builtin commands, shell scripts, and script arguments

A UNIX file system consists of disk partitions
File types and directory entries are stored as (name, inode-number) pairs
Links can be hard (inode: data stored and access to file data via direct and indirect blocks) or symbolic
Ownership of a file can be viewed using stat, fstat, and lstat commands, with permissions for user/group/other
Set UID and Set GID bits can be set, and access control can be modified using umask, chmod, and fchmod commands
Files can be managed using chown, fchown, link, unlink, rename, and utimes commands
Directories can be managed using mkdir, rmdir, chdir, and fchdir commands
File descriptors can be manipulated using opendir, closedir, readdir, telldir, seekdir, and rewinddir commands

Standard input, output, and error streams (stdin, stdout, stderr) can be buffered, line-buffered, or unbuffered
Files can be opened using fopen, freopen, and fdopen commands
Buffering modes can be set using setbuf and setvbuf commands
File input/output can be performed using fgetc, ferror, feof, clearerr, and ungetc commands
Formatted input/output can be performed using fgets, fputs, and printf commands
Binary input/output can be performed using fread, fwrite, ftell, fseek, fgetpos, and fsetpos commands

/etc/passwd and /etc/group files store user and group information
User and group information can be retrieved using getpwuid, getpwnam, getpwent, setpwent, and endpwent commands
Supplementary Group IDs can be used to add groups to a user
/etc directory stores system information
uname(1) and uname(3) commands provide system information
Time-related functions include time, ctime, strftime, gettimeofday, and others
Time zone issues can be handled using certain functions

Process ID (pid) and group ID (gid) can be used to manage processes
fork function creates a new process, and exit function terminates a process
wait and waitpid system calls can be used to wait for a process to terminate
WIFEXITED() and WEXITSTATUS() macros provide exit status information
Zombie processes can be terminated using wait, waitpid, wait3, and wait4 commands

Pipes enable interprocess communication
Kernel pipe, pipe(2) system call creates a pipe
Pipes have read and write ends
Termination conditions include EOF on read and SIGPIPE on write
One-way communication can be achieved from child to parent, or parent to child using pipes
popen(3) and pclose(3) commands can be used to create and manage pipes
micro shell concepts include exit values, expansion, environment variables, builtin commands, shell scripts, and script arguments