Overall Assignment - Must get everything co
ect to get extra credit
Write a program (in C) called extra.c targeted at the Linux platform. Your program will spawn a child process with a
pipe shared between the parent and child. The parent will write to the pipe and the child will read from it. There are no
equired command line arguments.
The parent process will intercept SIGINT and, when a SIGINT is detected by the parent, it will prompt the user for a
single line text message. Once having received the message from the user, the parent will send (write) the message to the
child via the shared pipe and send a SIGFPE signal to the child to get its attention. The parent process will repeat this
ehavior for any SIGINT it receives, until an ”exit” message is received from the user (see below).
The child process must ignore SIGINT. When the child process detects a SIGFPE, it will read a single line message (less
than 512 bytes) from the shared pipe. The first token of the message may optionally be an integer representing a time
in seconds (DELAY). If the first token is not an integer, assume that the DELAY value is 5 seconds and the non-intege
token is then part of the message. The child will print the message (minus the leading integer, if any) to standard output.
It will repeat printing the message every DELAY seconds until the next SIGFPE is intercepted and a new message is read
from the parent.
Below is an example where there is 10 seconds between each inte
upt and input from the user.
Example:
# ./extra
^CInte
upt received, enter new message: 2 how are you
how are you
how are you
how are you
how are you
how are you
^CInte
upt received, enter new message: hows it going
hows it going
hows it going
Specifications and Restrictions
• (Required) Makefile containing at least 3 rules:
1. all: (compiles everything together and produces an executable)
2. clean: (removes all object and temporary files)
3. run: (command for running your executable that works with the submitted code)
• (Required) Program must work on the lab machines with various forms of input. Consider edge cases carefully.
• (Required) Must be robust, including e
or catching. You must catch e
ors and print out an appropriate e
o
message containing the e
no and the message produced by that e
or. This means you will need e
no.h and
string.h, li
aries at least.
• (Required) Implementation of the repetition interval shall be done using signal(), pause() and alarm(). Use of
the li
ary function sleep() and busy wait loops are not permitted.
• (Required) If the parent receives a message of “exit” from the user, the parent forwards the message to the child
and waits for it to exit (terminate) and then performs its own exit. Upon receipt of the “exit” message, the child
prints a message to standard out indicating its intention to exit and then exits.
• Helpful functions: fork, signal, pause, alarm, close, exit, fgets, sscanf etc. (consult man pages as needed)
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What to turn in (in a zip on Canvas, yes Canvas):
• extra.c (no header files)
• Makefile
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