System ProgrammingProject #1 Concepts

Assignment #1 . (Hint, fork, exec, wait system call ) redirection (< , >) . (Ex, a.out > a.result a.out a.result .) pipe (|) . Unix FIFO pipe 2 . : !

Key conceptForkstdin/stdoutRedirectionPipe

1-0. Program vs. ProcessProgram Instruction Process program instanceOS ,

, ?) client ?) ,

1-1. fork()Processfork()ProcessProcess*. *. *. PID *. Process .

pid = fork();If(pid!=0) { /* section A */}else{ /* section B */}pid = fork();If(pid!=0) { /* section A */}else{ /* section B */}pid = fork();If(pid!=0) { /* section A */}else{ /* section B */}*. Parent Processfork() return value Child process id*. Child Process-fork() return value 0-process id 0

1-2. exec()ProcessFork()ProcessProcess*. Process !*. Exec()Process X

2-1. Stdin, Stdout (device) * !* OS

2-2. Stdin, Stdoutstdin : Standard input , stdout : Standard output , Standard . File open->read or write->close

3. Shell?The interface with the UNIX) bash, csh, tcsh c.f.) GUI (Graphic User Interface)stdin stdout

4. Redirection . .> : .< : .>> : > overwrite append . Ex) .

example

5-1. Pipeline redirection Data . Redirection . ?

5-2 UNIX FIFO pipemkfifoCreate named pipes

5-3. Filter Data wc(word count) : , , .sort : .

Filter Pipeline Redirection .

example

example

example

1-1. Adam server Sun OS 5.9 PC Linux VMWare XP . =)

1-2. Adam

2. compile

gcc filename.c a.out gcc filename.c o filename2 filename2

3.

: tar cvzf filename.tar.gz directory : tar xvzf filename.tar.gz

4-1. Makefile main.c, read.c, write.c io.h . test. gcc c main.cgcc c read.cgcc c write.cgcc main.o read.o write.c o test!! -> Makefile !!

4-2. Makefile cont. Makefile make directory makefile target : dependencycommandcommand Tab make clean

4-3. Makefile cont.test : main.o read.o write.o gcc main.o read.o write.o -o test main.o : io.h main.c gcc -c main.c read.o : io.h read.c gcc -c read.c write.o: io.h write.c gcc -c write.c clean: rm f *.o test