Subject: UNIX System Programming
Subject Code: CE61
I. Introduction.
What is a POSIX standard ? Expalin different subsets of POSIX standard. Write the structure of the program to filterout non- POSIX complaint codes from a user program.
Write a C/C++ POSIX compalint program to check the following limits:
a. Number of clock ticks
b. Maximum number of child processes
c. Maximum path length
d. Maximum character in a filename
e. Maximum number of open files per process.
List out all POSIX.1 and POSIX.1b defined system configuration limits in manifested constants with compailetime limit, minimum value and meaning.
Differentiate between ANSI C and C++ standards.
Describe the characteristics of POSIX.1 FIPS standard and X/open standard.
Expalin the common characteristics of API and describe the error status codes.
II. UNIX Files.
1. Explain the different file types available in UNIX or POSIX systems.
2. Describe the unix kernel suppoprt for files.
3. Write the code segment in C that reads utmost 100 bytes into a variable but from standard input.
4. List and expalin the access mode flags and access modifier flags. Also explain how the permission value spesified on
open call is modified by the calling process umask value.
5. Expalin how API can be used for file and record locking.
6. Give the hierarchy structure of the file classes.
7 Differentiate between Hard links and symbolic links with an examples.
8 Expalin process of changing user and group ID of files.
9. What are named pipes ? Expalin with an examples the use of lseek, link,access, with
their prototypes and argument values.
10. What are POSIX file attributes, describe with examples, also expalin various commands to change file attributes.
11. Describe the inode table entries.
12. Derive with neat block diagram sharing of open files between parent and child after fork.
13. What are process identifiers ? Mention the commands for getting different IDs of calling process.
III. UNIX Process.
1. What is fork and vfork ? Expalin with an examples program for each.
2. Describe the UNIX kernel support for a process. Show the related data structures .
3. Write a program in C/C++ to obtain process attributes.
4. What is job control ? Summarize the job control features with the help of a figure.
5. Expalin the different exec functions? Describe how the functioning differ from each other.
6. Expalin how process accounting is done in UNIX system. Write a program to generate accounting data and give its process structure.
7. What is a controlling terminal ? Explain its characteristics and relation to session and process groups.
8. What are interpreter files ? Expalin.
9. Describe with block diagrams the sequence of processes involved for network login.
10. Expalin with neat sketch summary of job control features with foreground and background jobs.
11. What is a signal? How can it be generated ? Also explain kernels action on signal.
12. Describe the actions of the following signals.
a. SIG QUIT
b. SIG TTIN
c. SIG WINCH
d. SIG CHLD
e. SIG HUP
IV. Signals and Daemon Processes
1. What is a signal ? Discus any five POSIX defined signals. Expalin how to setup a signal handler.
2. What is a daemon ? Give its basic coding rules.
3. How daemon handlers error lagging ? Describe in detail with block diagrams SVR4 streams log driver and BSD syslog facility.
4. Expalin with prototypes kill function, sigsetjmp and siglongjmp APIs.
5. Write a program in C to set up a real time clock internal time using alaram API.
V. Interprocess Communication.
1. What are pipes ? Expalin their limitations. Expalin how pipes are created and used in IPC with an examples.
2. Exp thalin in the UNIX kernel support for messages. Show the related data structures.
3. Exalin identifier,key and permission structure of IPC.
4. Describe the message queue ID structure and different function calls of message queue.
5. Give an overview of IPC methods.
6. Expalin p open and p close functions with prototypes and write a program to demonstarte the p open and p close functions.
7. What is the need for sigproc mask function ?
VI. Short notes
1. Race condition
2. Zombie Process
3. Network Login
4. Co Process
5. Interval timers.
6. Shared memory
7. Stream pipe
8. Environment list
9. Client Server interactio.
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