CSC322 C Programming and UNIX - Department of Computer ...

More documents

Recommendations

Info

Counterpoint UNIX was developed on small machines and became popular on the “killer micros”. UNIX dialects now run on everything from a PDA to CRAY supercomputers UNIX is based on simple and elegant principles (but has added a some cruft over the years) UNIX is not particularly hard to use (compared to the power it gives to the user), but has a reasonably steep learning curve. It’s not a “show-me” operating system, but a “tell me” operating system, UNIX has been created in a research environment, and much of it has been developed in informal settings by hackers. Much of the impetus for UNIX comes from free versions (Linux, Net-, Open-, FreeBSD), although many companies contribute to it’s development Many UNIX kernels are monolithic, but the UNIX system is extremly modular. Stephan Schulz 8
UNIX First portable operating system (NetBSD: 18 processor architecures, ≈ 50 computer architecures) Written in a “high-level” language (C) Small (for what it does): – Recent LINUX kernel: 2.4 million LOC (1.4 million for driver, 0.4 million architecture-dependent stuff (16 ports) – Windows 2000: Estimates range from 29 million to 65 million LOC, supports just 1.5 architecures Modular (though often on a monolithic kernel) – Separate windowing system (X) and window managers – Various Desktop-Solutions (CDE, KDE, Gnome) – Toolbox-philosphy: Combine (lot’s of) simple tools – Underneath: Strong and simple abstraction (“Everything is a file”) Stephan Schulz 9
Page 1 and 2: CSC322 C Programming and UNIX Steph
Page 3 and 4: The UNIX Operating System UNIX and
Page 5 and 6: The UNIX Operating System UNIX and
Page 7: UNIX is a big-iron operating system
Page 11 and 12: UNIX history tree (simplified) For
Page 13 and 14: 1978 3BSD, adding virtual memory 19
Page 15 and 16: A Short History of UNIX and C 1991
Page 17 and 18: Another Opinion UNIX is not an oper
Page 19 and 20: Upshot You don’t have to grow a b
Page 21 and 22: Shell UNIX Architecture Libraries U
Page 23 and 24: Some Concepts UNIX is a multi-user
Page 25 and 26: UNIX: Provide Tools, Not Policy The
Page 27 and 28: Default KDE Desktop (SuSE Linux) St
Page 29 and 30: KDE Desktop with Terminal Applicati
Page 31 and 32: Text Interface Example (contd.) Mos
Page 33 and 34: Typical File System Layout / (Root
Page 35 and 36: More about files We can use the -l
Page 37 and 38: GNU info files UNIX Online Document
Page 39 and 40: CSC322 C Programming and UNIX UNIX
Page 41 and 42: Command Types There are different t
Page 43 and 44: UNIX User Commands: rm, mkdir, rmdi
Page 45 and 46: Effective Shell Use: Editing/Comple
Page 47 and 48: Example: File Handling and Globbing
Page 49 and 50: UNIX User Commands: cat/more/less c
Page 51 and 52: Getting into it: vi vi flyby Modal
Page 53 and 54: Emacs for Everyone Getting into it:
Page 55 and 56: Emacs for Everyone III Emacs is non
Page 57 and 58: ed is the standard text editor When
Page 59 and 60:
? ? quit ? exit ? bye ? hello? ? ea
Page 61 and 62:
SO-CALLED "VISUAL" EDITORS HAVE BEE
Page 63 and 64:
Usage: grep . . . UNIX User Comma
Page 65 and 66:
Simple Output Redirection You can r
Page 67 and 68:
Input Redirection You can also redi
Page 69 and 70:
Basic Process Control You can start
Page 71 and 72:
Job Control Example $ emacs & (Star
Page 73 and 74:
CSC322 C Programming and UNIX Progr
Page 75 and 76:
Consider the following C program #i
Page 77 and 78:
#include #include int main(void)
Page 79 and 80:
A Closer Look (4) gcc is the GNU C
Page 81 and 82:
The Fahrenheit-Celsius Example Comp
Page 83 and 84:
Variables “int fahrenheit, celsiu
Page 85 and 86:
A while-loop has the form while()
Page 87 and 88:
UNIX User Commands: cp and mv cp wi
Page 89 and 90:
Page 91 and 92:
Flow-Control: if The primary means
Page 93 and 94:
Flow-Control: for The for-loop in C
Page 95 and 96:
for vs. while Note that for is more
Page 97 and 98:
Types: Integers and Characters C ha
Page 99 and 100:
Simple Character I/O The C library
Page 101 and 102:
Page 103 and 104:
Exercises Write a programm that con
Page 105 and 106:
Nomination: Most Useless Use of cat
Page 107 and 108:
Example: Word Counting /* Count wor
Page 109 and 110:
Another View at Expressions Express
Page 111 and 112:
Expressions: Associativity of Binar
Page 113 and 114:
Expressions: Logical Operators Logi
Page 115 and 116:
Floating Point Numbers C supports t
Page 117 and 118:
Administrative Notes Please ssh to
Page 119 and 120:
Page 121 and 122:
#include #include #include int m
Page 123 and 124:
Initializing Arrays In the example,
Page 125 and 126:
No Safety Belts and No Air Bag! C d
Page 127 and 128:
Functions Functions are the primary
Page 129 and 130:
Function Calling A function is call
Page 131 and 132:
Example: Printing Character Frequen
Page 133 and 134:
Assignment A prime number is a (pos
Page 135 and 136:
A function is a named subroutine Re
Page 137 and 138:
Example: int read int10(void) /* We
Page 139 and 140:
Do we have a Valid Digit? /* Is a c
Page 141 and 142:
Build General Functions! Good progr
Page 143 and 144:
Example: Printing Integers We now w
Page 145 and 146:
Writing a Number in any Base (
Page 147 and 148:
Putting Things Together: A Base Con
Page 149 and 150:
Usage Example $ ./base converter In
Page 151 and 152:
Page 153 and 154:
Includes Translates into Is combibe
Page 155 and 156:
The C Preprocessor The C preprocess
Page 157 and 158:
myfile.c: A Poem #include "mary" $
Page 159 and 160:
Simple Macro Definitions: #define T
Page 161 and 162:
Macros with Arguments Macro definit
Page 163 and 164:
#define Caveats Since macros work b
Page 165 and 166:
cond preproc.c: #define hallo #defi
Page 167 and 168:
Page 169 and 170:
cond preproc.c: #define hallo #defi
Page 171 and 172:
Combinations of #ifdef and #include
Page 173 and 174:
Definitions and Declarations Defini
Page 175 and 176:
Scoping Rules There are two kinds o
Page 177 and 178:
Limiting Potential Scope By default
Page 179 and 180:
Persistent Local Variables: static
Page 181 and 182:
Example: Static and Automatic Varia
Page 183 and 184:
Implement the libray in its own sou
Page 185 and 186:
Project: An RPN Calculator Aim: A c
Page 187 and 188:
$ ./rpn calc Usage Example 10 8 + S
Page 189 and 190:
Subtasks From the above, we can ide
Page 191 and 192:
The Character I/O Library: Ideas Ma
Page 193 and 194:
The Character I/O Library: Global V
Page 195 and 196:
int LookChar(void) { int c = GetCha
Page 197 and 198:
#include "chario.h" The Integer I/O
Page 199 and 200:
The Integer I/O Library: Helper fun
Page 201 and 202:
The Integer I/O Library: Helper fun
Page 203 and 204:
The Integer I/O Library: Checking f
Page 205 and 206:
Exercises Download the program from
Page 207 and 208:
Recapitulation: Some of our Library
Page 209 and 210:
Case Distinctions Note: The operato
Page 211 and 212:
The Stack Abstract Datatype A stack
Page 213 and 214:
Pushing things onto the stack: PUSH
Page 215 and 216:
The Main Program: Prelimaries and D
Page 217 and 218:
The Main Loop: Arithmetic operators
Page 219 and 220:
The Main Loop: I/O operators switch
Page 221 and 222:
case ’S’: for(i=0; i
Page 223 and 224:
UNIX User Commands: dc dc is an arb
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Bitwise Operators Bitwise operators
Page 231 and 232:
Example These macros can be used to
Page 233 and 234:
Conditional Expressions Similarly t
Page 235 and 236:
Type Conversion (Casting) As alread
Page 237 and 238:
Page 239 and 240:
Order Of Execution In general, the
Page 241 and 242:
Types in C C offers a set of basic
Page 243 and 244:
Defining New Types with typedef The
Page 245 and 246:
Enumerations in C Enumeration data
Page 247 and 248:
enum and typedef Typically, enumera
Page 249 and 250:
Aggregating Data Types Let’s agai
Page 251 and 252:
Consider the following definition:
Page 253 and 254:
Exercises Create a function that ha
Page 255 and 256:
Assume the following problem: Repre
Page 257 and 258:
typedef enum { circle, square, rect
Page 259 and 260:
typedef union { CircleCoord circle_
Page 261 and 262:
Pointers Pointers are derived types
Page 263 and 264:
#include #include void swap(int *
Page 265 and 266:
Why Pointers? The are two main reas
Page 267 and 268:
Exercises Write a program that prin
Page 269 and 270:
Refresher: Pointers A pointer type
Page 271 and 272:
The malloc() function We request a
Page 273 and 274:
More on Dynamic Memory Allocation G
Page 275 and 276:
Example: SecureMalloc() Note: In my
Page 277 and 278:
Example: Linear Lists (of Integers)
Page 279 and 280:
#ifndef INT_LISTS #define INT_LISTS
Page 281 and 282:
Example - Inserting At the End /* I
Page 283 and 284:
Example - Freeing Lists /* Free the
Page 285 and 286:
Example - Main Function int main(vo
Page 287 and 288:
Use this datatype and the functions
Page 289 and 290:
Monday, Oct. 14th, 11:00 - 11:50 To
Page 291 and 292:
Refresher: Dynamic Memory Handling
Page 293 and 294:
int array[10]; int *a, *b; a = arra
Page 295 and 296:
Compiling: gcc -o csc322 csc322.c R
Page 297 and 298:
#include #include #include void
Page 299 and 300:
CSC322 C Programming and UNIX Midte
Page 301 and 302:
The File System / (Root directory)
Page 303 and 304:
Some Important UNIX Commands (1) Or
Page 305 and 306:
Input and Output Redirection, Pipin
Page 307 and 308:
C Compiling with gcc Programs consi
Page 309 and 310:
if...else - Conditional execution s
Page 311 and 312:
C Preprocessor The #include directi
Page 313 and 314:
Page 315 and 316:
#include #include #define BUF_SIZ
Page 317 and 318:
Example: Growing the Buffer as Need
Page 319 and 320:
char *cp, *cq; int *ip, *iq; Pointe
Page 321 and 322:
Reading the Command Line: argc and
Page 323 and 324:
#include #include Example: Echoin
Page 325 and 326:
CSC322 C Programming and UNIX Makin
Page 327 and 328:
chario.h The rpn calc Example (Simp
Page 329 and 330:
UNIX User Utilities: make make is a
Page 331 and 332:
Built-In Rules and Makefile Variabl
Page 333 and 334:
Phony Targets Not all targets need
Page 335 and 336:
CSC322 C Programming and UNIX Odds
Page 337 and 338:
Assertions Internal consistency che
Page 339 and 340:
#include #include #include int g
Page 341 and 342:
Search in Loops A frequent use of l
Page 343 and 344:
Selective Operations and Special Ca
Page 345 and 346:
do/while Loops Both while and for l
Page 347 and 348:
E theorem prover Some Loop Statisti
Page 349 and 350:
CSC322 C Programming and UNIX Funct
Page 351 and 352:
Function Pointers We can use the ad
Page 353 and 354:
Example #include #include int add
Page 355 and 356:
C Library Functions: qsort() qsort(
Page 357 and 358:
#include #include Example typedef
Page 359 and 360:
Unsorted: 103 70 105 115 81 127 74
Page 361 and 362:
C Standard Library Organisation - a
Page 363 and 364:
#include #include #include #incl
Page 365 and 366:
CSC322 C Programming and UNIX C Sta
Page 367 and 368:
Some C Character Classes All charac
Page 369 and 370:
#include #include #include int m
Page 371 and 372:
Strings Strings are not part of the
Page 373 and 374:
Example: Duplicating Strings Severa
Page 375 and 376:
String Functions from (3) int strc
Page 377 and 378:
Generic Memory Access Functions The
Page 379 and 380:
Memory Functions from (2) void *me
Page 381 and 382:
Page 383 and 384:
Memory Functions from (1) void *me
Page 385 and 386:
Example #include #include #includ
Page 387 and 388:
Input and Output in the Standard Li
Page 389 and 390:
Opening File Streams In addition to
Page 391 and 392:
Simple Stream Based I/O Functions (
Page 393 and 394:
Page 395 and 396:
} for(i=1; i
Page 397 and 398:
Exercises Write a version of memmov
Page 399 and 400:
Remark about fgets() char *fgets(ch
Page 401 and 402:
int main(int argc, char *argv[]) {
Page 403 and 404:
$ man man | ./mycat1 Example Output
Page 405 and 406:
Buffering and Flushing Both input a
Page 407 and 408:
#include #include int main(int ar
Page 409 and 410:
More Operations on Files int remove
Page 411 and 412:
Error Functions Each FILE data stru
Page 413 and 414:
Page 415 and 416:
A first Example printf("%d divided
Page 417 and 418:
Format Specifiers Format specifiers
Page 419 and 420:
Some Conversion Letters (2) f: Prin
Page 421 and 422:
Page 423 and 424:
Size Modifiers Size modifiers are u
Page 425 and 426:
The Flags -: Left-justify output (o
Page 427 and 428:
#include #include Example int mai
Page 429 and 430:
$ arch322 Makefile sort_csc322.c ut
Page 431 and 432:
Processes A UNIX process is an inst
Page 433 and 434:
$ ps PID TTY TIME CMD 1125 pts/3 00
Page 435 and 436:
$ ps aux Interesting ps Example USE
Page 437 and 438:
Signals Signals are a way to signal
Page 439 and 440:
Some UNIX Signals UNIX defines abou
Page 441 and 442:
top is an interactive version of ps
Page 443 and 444:
Catching Signals User programs can
Page 445 and 446:
ANSI C Signal Handling with signal.
Page 447 and 448:
ANSI C Signal Handers A signal hand
Page 449 and 450:
Page 451 and 452:
int main(int argc, char* argv[]) {
Page 453 and 454:
Exercises Start a long running proc
Page 455 and 456:
UNIX philosophy: Everything is a fi
Page 457 and 458:
FIFOs (named pipes) UNIX File Types
Page 459 and 460:
The stat() Functions (2) All three
Page 461 and 462:
Page 463 and 464:
} Example Continued else if(S_ISLNK
Page 465 and 466:
Example Output (of device directory
Page 467 and 468:
Links (2) Soft links create indirec
Page 469 and 470:
Exercises Read man stat and extend
Page 471 and 472:
All files have an owner (a user) Fi
Page 473 and 474:
User Groups Groups are used in UNIX
Page 475 and 476:
UNIX User Utilities: chown and chgr
Page 477 and 478:
Symbolic Encoding ls -l prints a st
Page 479 and 480:
Examples rw-r--r-- is the most comm
Page 481 and 482:
chmod Examples chmod ugo+rwx myfile
Page 483 and 484:
Exercises Read the man and info pag
Page 485 and 486:
File Decriptors Files are identifie
Page 487 and 488:
Option flags for open() Note: All o
Page 489 and 490:
Notes on open() and close() The mod
Page 491 and 492:
Page 493 and 494:
} Example Continued while((count =
Page 495 and 496:
Cheating with fdopen() Formatted, b
Page 497 and 498:
CSC322 C Programming and UNIX More
Page 499 and 500:
FILE* myfile Standard IO Library Th
Page 501 and 502:
Manipulating File Descriptors: fcnt
Page 503 and 504:
Page 505 and 506:
if(flags & O_APPEND) { printf("Appe
Page 507 and 508:
Multiplexing I/O Often, a program h
Page 509 and 510:
select() Arguments fd set is define
Page 511 and 512:
Page 513 and 514:
$ ./select_example 2 file descripto
Page 515 and 516:
CSC322 C Programming and UNIX Basic
Page 517 and 518:
Networking Stephan Schulz 517
Page 519 and 520:
Page 521 and 522:
Page 523 and 524:
Networking Concepts Is communicatio
Page 525 and 526:
Level 2 protocol (Hardware-Agnostic
Page 527 and 528:
The Transmission Control Protocol (
Page 529 and 530:
A server offers a certain service C
Page 531 and 532:
The Client Side for TCP Connections
Page 533 and 534:
Creating Sockets with socket() (2)
Page 535 and 536:
Socket Adresses for IPv4 For IPv4 a
Page 537 and 538:
Connecting to a Remote Port: connec
Page 539 and 540:
Example (2) sock = socket(PF_INET,
Page 541 and 542:
The Server Side A server has a more
Page 543 and 544:
Naming a Socket (Binding a Socket t
Page 545 and 546:
Accepting Connections To finally es
Page 547 and 548:
Example (2) if(argc!=2) { fprintf(s
Page 549 and 550:
man pages: - man socket - man 2 bin
Page 551 and 552:
CSC322 C Programming and UNIX Proce
Page 553 and 554:
Process Properties For each process
Page 555 and 556:
Exiting There are three normal ways
Page 557 and 558:
Cleaning up: atexit() ANSI C allows
Page 559 and 560:
Example (2) int main(void) { if(ate
Page 561 and 562:
Running other Programs: system() Th
Page 563 and 564:
Termination Status Interpretation T
Page 565 and 566:
Example: Executing Commands int mai
Page 567 and 568:
Exercises Write a program that prin
Page 569 and 570:
Creating new Processes: fork() The
Page 571 and 572:
} Example if(child_pid == 0) { pid
Page 573 and 574:
Comments on fork() Order of executi
Page 575 and 576:
#include int main(int argc, char*
Page 577 and 578:
FILE* myfile Standard IO Library I/
Page 579 and 580:
Example: Bufferd I/O and Forking /*
Page 581 and 582:
Waiting for Children to Die As stat
Page 583 and 584:
Example (2) for(i=0; i
Page 585 and 586:
Output: Example Output Parent. My P
Page 587 and 588:
CSC322 C Programming and UNIX Proce
Page 589 and 590:
Getting and Changing Process Groups
Page 591 and 592:
Example (2) res = setpgid(0,0); if(
Page 593 and 594:
Example Output $ ./pg example Paren
Page 595 and 596:
Is this good for Something? There a
Page 597 and 598:
Example (2) pid = getpid(); pgid =
Page 599 and 600:
Example Output with kill Queen bee:
Page 601 and 602:
Waiting for Termination: waitpid()
Page 603 and 604:
Exercises Write a program that keep
Page 605 and 606:
Process Environment Each UNIX proce
Page 607 and 608:
$ printenv Example: Part of my Envi
Page 609 and 610:
Accessing the Environment from a Pr
Page 611 and 612:
The POSIX Interface to the Environm
Page 613 and 614:
The 6 exec Functions #include int
Page 615 and 616:
Page 617 and 618:
int count_words(char* line) { int w
Page 619 and 620:
} Example (5) for(i=0; i
Page 621 and 622:
int main(void) { pid_t child_pid; c
Page 623 and 624:
} { /* Parent */ setpgid(child_pid,
Page 625 and 626:
# ls * Command: ls Arguments: ls *
Page 627 and 628:
CSC322 C Programming and UNIX Final
Page 629 and 630:
Pointers and Dynamic Arrays Arrays
Page 631 and 632:
New Flow Control Constructs break i
Page 633 and 634:
Standard Library: Characters and St
Page 635 and 636:
Standard Library: Buffered I/O Stan
Page 637 and 638:
Processes and Signals Processes are
Page 639 and 640:
UNIX: Everything is a file File typ
Page 641 and 642:
File Descriptors and select() File
Page 643 and 644:
TCP/IP (v4) Connections Reliable, s
Page 645 and 646:
Process Environment and Program Exe
show all

CSC322 C Programming and UNIX - Department of Computer ...

Create successful ePaper yourself

Delete template?

Save as template?