COMP9044 - Week 10 - Laboratory Exercises - Solved

Before the lab you should re-read the relevant lecture slides and their accompanying examples.

 

 

Create a new directory for this lab called lab10, change to this directory, and fetch the provided code for this week by running these commands:

$ mkdir lab10 

$ cd lab10 

$ 2041 fetch lab10 
Or, if you're not working on CSE, you can download the provided code as a zip file or a tar file.

 

 

Write a Shell program, which_webserver.sh which given the URL of 1 or more webservers as command-line arguments prints what software the webserver is running, as indicated by the server field returned in a request to the web server.

Match the output and behaviour in the example below exactly:

$ ./which_webserver.sh https://www.unsw.edu.au https://www.unsw.edu.au Apache/2.4.34 (Red Hat) OpenSSL/1.0.1e-fips PHP/5.6.25 

$ ./which_webserver.sh https://www.google.com https://www.google.com gws 

$ ./which_webserver.sh https://www.netflix.com https://www.netflix.com nq_website_nonmember-prod-release b2b0bc7b-bffd-4024-b8b8-d060e658f2ac $ ./which_webserver.sh https://www.abc.net.au https://www.sydney.edu.au http://www.bom.gov.au https://www.abc.net.au Apache/2.4.43 (Unix) https://www.sydney.edu.au Apache http://www.bom.gov.au Apache
Hint

man curl

Assumptions
Your answer must be Shell. You can not use other languages such as Perl, Python or C.

No error handling is necessary.


 

Write a Shell program, make_tree.sh which is given the pathname of a directory tree.

It should search this directory tree for directories containing a makefile.

For each of these directories it shouldprint the directory pathname and then run make in the directory.

Match the output and behaviour in the examples below exactly:


 

$ unzip /web/cs2041/20T2/activities/make_tree/examples.zip 

$ find simple simple simple/b.c simple/Makefile 

$ ./make_tree.sh simple/ Running make in simple clang -Wall   -c -o b.o b.c clang -Wall -o p b.o $ find medium medium medium/a medium/a/x.c medium/a/h.c medium/a/Makefile medium/a/l.c medium/b medium/b/b.c medium/b/j.c medium/b/k.c medium/c medium/c/p.c medium/c/Makefile $ ./make_tree.sh medium Running make in medium/a clang -Wall   -c -o h.o h.c clang -Wall   -c -o l.o l.c clang -Wall   -c -o x.o x.c clang -Wall -o c h.o l.o x.o Running make in medium/c clang -Wall   -c -o p.o p.c clang -Wall -o d p.o 

$ find hard hard hard/a hard/a/p.c hard/a/r.c hard/a/Makefile hard/a/q.c hard/b hard/b/b hard/b/b/b hard/b/b/b/b hard/b/b/b/b/b hard/b/b/b/b/r.c hard/b/b/b/b/Makefile hard/c hard/c/d hard/c/d/o.c hard/c/d/Makefile hard/c/e hard/c/e/a.c hard/c/e/b.c hard/c/e/f hard/c/e/f/a.c hard/c/e/f/Makefile $ ./make_tree.sh hard Running make in hard/a clang -Wall   -c -o p.o p.c clang -Wall   -c -o r.o r.c clang -Wall   -c -o q.o q.c clang -Wall -o b p.o r.o q.o Running make in hard/b/b/b/b clang -Wall   -c -o r.o r.c clang -Wall -o r r.o Running make in hard/c/d clang -Wall   -c -o o.o o.c clang -Wall -o m o.o Running make in hard/c/e/f clang -Wall   -c -o a.o a.c clang -Wall -o i a.o 
The test directories are also available as a zip file



 
 
 

If make_tree.sh is give extra command line arguments they should be passed to each make command, for example:

$ cat simple/Makefile  

CC=clang CFLAGS=-Wall 

p: b.o 

$ (CC) $(CFLAGS) -o $@ $^ 

.PHONY: clean 

clean:     rm -f b.o 

clobber: clean     rm -f p 

$ ./make_tree.sh medium clobber Running make in medium/a rm -f h.o l.o x.o rm -f c

Running make in medium/c rm -f p.o rm -f d

$ ./make_tree.sh hard clean Running make in hard/a rm -f p.o r.o q.o 

Running make in hard/b/b/b/b rm -f r.o 

Running make in hard/c/d rm -f o.o 

Running make in hard/c/e/f rm -f a.o 
Hint

Use find to find all Makefiles in the directory tree.



Your answer must be Shell. You can not use other languages such as Perl, Python or C.

No error handling is necessary.


Write a Shell program, compress_if_needed.sh which takes the pathnames of 0 or more files as command line arguments.

It should compresses each file with xz if and only if, this results in a smaller file.

Match the output and behaviour in the example below exactly:

$ unzip /web/cs2041/20T2/activities/compress_if_needed/examples.zip 

$ ls -l file* 

-rw-r--r-- 1 andrewt andrewt 4096 Aug  3 17:10 file1.bin

-rw-r--r-- 1 andrewt andrewt 4096 Aug  3 17:10 file2.bin

$ ./compress_if_needed.sh file1.bin file2.bin file1.bin 4096 bytes, compresses to 4156 bytes, left uncompressed file2.bin 4096 bytes, compresses to 2160 bytes, compressed 

$ ls -l file* 

-rw-r--r-- 1 andrewt andrewt 4096 Aug  3 17:10 file1.bin

-rw-r--r-- 1 andrewt andrewt 2160 Aug  3 17:10 file2.bin.xz 
The two test files are also available as a zip file

Assumptions
Your answer must be Shell. You can not use other languages such as Perl, Python or C.

You should use xz's default compression. xz has many options to change compression behaviour. Do not use these.