• introduction of structs
• string operations

Before the lab you should re-read the relevant lecture slides and their accompanying examples. You should also have read the lab assessment guidelines.

Create a new directory for this lab called lab09 by typing:

mkdir lab09

Change to this directory by typing:

cd lab09

A citizen science project monitoring whale populations has files of containing large numbers of whale observations. Each line in these files contains:

• the date the observation was made
• the number of whales in the pod
• the species of whales

Here is a file of example data which you can download to test your program. It looks like this:

head whales.txt
18/01/18  9 Pygmy right whale
01/09/17 21 Southern right whale
16/02/18  4 Striped dolphin
02/07/17  4 Common dolphin
19/02/18  4 Blue whale
21/02/18 38 Dwarf sperm whale
14/06/17 29 Southern right whale
20/06/17  3 Spinner dolphin
22/07/17 34 Indo-Pacific humpbacked dolphin
20/03/18  7 Long-finned pilot whale

Here is the starting code for this exercise.

It already contains the functions which you discussed in your tutorial which reads the file of whale sightings into an array of structs. You do not need need to change these functions.

The main function in orca.c has this code:

int n_orca_pods = count_orca_sightings(n_sightings, whale_sightings);
printf("%d Orca sightings in %s\n", n_orca_pods, argv[1]);

Your task in this exercise is to complete this function:

int count_orca_sightings(int n_sightings, struct pod sightings[n_sightings]) {
    // REPLACE THIS COMMENT WITH YOUR CODE
    // THIS FUNCTION SHOULD NOT CALL SCANF OR PRINTF
    // IT SHOULD JUST RETURN A VALUE
    return 42; // CHANGE ME
}

Do not change any other function.

It should return a count of the number of sightings of Orca pods in the file.

Note, "pod" is the collective number for a group of whales. Your functions should return the number of Orca pods. It does not have have to sum the number of individual whales in these pods.

When you have completed the function count_orca_sightings this is how orca.c should behave:

dcc -o orca orca.c
./orca whales.txt
53 Orca sightings in whales.txt

Hint: hint use strcmp from string.h

Hint: most of the work for this exercise is figuring out what to do - only a short loop containing an if statement is needed.

Hint: if you are having trouble understanding structs COMP1511 tutors Dean Wunder and Ben Pieters-Hawke take you through the basics in this video:

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest orca

When you are finished on this exercise you and your lab partner must both submit your work by running give:

give cs1511 wk09_orca orca.c

Note, even though this is a pair exercise, you both must run give from your own account before Sunday 6 May 23:59:59 to obtain the marks for this lab exercise.

Here is the starting code for this exercise.

It already contains the functions which you discussed in your tutorial which reads the file of whale sightings into an array of structs. You do not need need to change these functions.

The main function in species_count.c has this code:

int pod_count;
int whale_count;
species_count(species, n_sightings, whale_sightings, &pod_count, &whale_count);
printf("%d %s pods containing %d whales in %s\n", pod_count, species, whale_count, filename);

Your task in this exercise is to complete this function:

void species_count(char species[], int n_sightings, struct pod sightings[n_sightings], int *n_pods, int *n_whales) {
    // REPLACE THIS COMMENT WITH YOUR CODE
    // THIS FUNCTION SHOULD NOT CALL SCANF OR PRINTF
    // IT SHOULD JUST ASSIGN VALUES to N_PODS AND N_WHALES
    *n_pods = 24; // CHANGE ME
    *n_whales = 42; // CHANGE ME
}

Do not change any other function.

species_count should assign the number of pods of the given species to *n_pods and the total number of whales of the given species to *n_whales

When you have completed the function species_count this is how species_count.c should behave:

dcc -o species_count species_count.c
./species_count whales.txt "Blue whale"
51 Blue whale pods containing 1171 whales in whales.txt
./species_count whales.txt "Indo-Pacific humpbacked dolphin"
43 Indo-Pacific humpbacked dolphin pods containing 897 whales in whales.txt

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest species_count

When you are finished on this exercise you and your lab partner must both submit your work by running give:

give cs1511 wk09_species_count species_count.c

Note, even though this is a pair exercise, you both must run give from your own account before Sunday 6 May 23:59:59 to obtain the marks for this lab exercise.

Here is the starting code for this exercise.

It already contains the functions which you discussed in your tutorial which reads the file of whale sightings into an array of structs. You do not need need to change these functions.

The main function in whale_summary.chas this code:

whale_summary(n_sightings, whale_sightings);

Your task in this exercise is to complete this function:

void whale_summary(int n_sightings, struct pod sightings[n_sightings]) {

    // PUT YOUR CODE HERE

}

Do not change any other function.

whale_summary should print for every whale species how many pods were seen and how many total whales were seen of that species.

Match the example output form EXACTLY, except you may print the lines in any order.

When you have completed the function whale_summary this is how whale_summary.c should behave:

dcc -o whale_summary whale_summary.c
./whale_summary whales.txt
59 Pygmy right whale pods containing 1260 whales
55 Southern right whale pods containing 1252 whales
68 Striped dolphin pods containing 1337 whales
62 Common dolphin pods containing 1232 whales
51 Blue whale pods containing 1171 whales
58 Dwarf sperm whale pods containing 1272 whales
52 Spinner dolphin pods containing 1118 whales
43 Indo-Pacific humpbacked dolphin pods containing 897 whales
50 Long-finned pilot whale pods containing 996 whales
68 Short-finned pilot whale pods containing 1344 whales
49 Dwarf minke whale pods containing 1080 whales
53 Orca pods containing 1245 whales
57 Pygmy sperm whale pods containing 1346 whales
55 Humpback whale pods containing 1071 whales
65 Fin whale pods containing 1251 whales
53 Coastal bottlenose dolphin pods containing 1169 whales
55 Sei whale pods containing 929 whales
47 Bryde's whale pods containing 1023 whales

You may assume there are at most 256 different whale species.

If autotest gives you an uninitialized variable error, you can reproduce this by compiling and running with dcc --valgrind, e.g.:

dcc --valgrind -o whale_summary whale_summary.c
./whale_summary whales.txt
Runtime error: uninitialized variable accessed.

Execution stopped here in whale_summary(n_sightings=1000, sightings=0x1ffee9fbf0) in whale_summary.c at line 113:
....

Beware the error may reported later than you expect.

Look back through your code for a variable, such as an array element, that has not been assigned an initial value before it is used.

Hint: if you are having trouble debugging your code watch COMP1511 tutor Peter Kydd explain how to add debugging printfs:

Hint: if you are having trouble with an uninitialized variable errors maybe Peter's explanation here will help:

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest whale_summary

When you are finished on this exercise you and your lab partner must both submit your work by running give:

give cs1511 wk09_whale_summary whale_summary.c

Note, even though this is a pair exercise, you both must run give from your own account before Sunday 6 May 23:59:59 to obtain the marks for this lab exercise.

The citizen scientists making whale observations have been careless entering whale names. They have often entered extra non-alphabetic characters or swapped upper case and lower case.

Here is an example of data they have entered you can download for this exercise.

We need a program to automatically correct the whale names they have entered.

Here is the starting code for this exercise.

It already contains the functions which you discussed in your tutorial which reads the file of whale sightings into an array of structs. You do not need need to change these functions.

You will notice the main function in sanitize_whales.c calls this function. The main function in sanitize_whales.chas this code:

sanitize_whales(species_names_file, n_sightings, whale_sightings);

Your task in this exercise is to complete this function:

void sanitize_whales(char species_names_file[], int n_sightings, struct pod sightings[n_sightings]) {
    // REPLACE THIS COMMENT WITH YOUR CODE
    // THIS FUNCTION SHOULD NOT CALL SCANF OR PRINTF
    // IT SHOULD CHANGE THE STRUCTS IN THE ARRAY SIGHTINGS
}

The species_names_file will be the name of a file with the correct whale name one per line.

Here is an example whale names file you can download for this exercise.

sanitize_whales should delete any extra non-alphabetic characters in the whale name and it should correct the case of the whale name.

When you have completed the function sanitize_whales this is how sanitize_whales.c should behave:

dcc -o sanitize_whales sanitize_whales.x
cat unsanitized_whales.txt
18/01/18  9 Pygmy  right whale
01/09/17 21  Southern       right whale
16/02/18  4 Striped dolphin
02/07/17  4 common dolphin
19/02/18  4 BLUE WHALE
21/02/18 38 Dwarf-sperm-whale
14/06/17 29    Southern64376537653right76532765353whale
20/06/17  3 Spinner35879875dolphin843729879324832978
22/07/17 34 indoPacifichumpbackeddolphin
20/03/18  7 ~`,.?<>:;"'[]Long-finned~`,.?<>:;"'[]pilot~`,.?<>:;"'[]whale
11/03/18 19        ____short       ____finned       ____PILOT       ____WHALE
24/09/17  5 S   outh----ern ri'ght wH78ale
./sanitize_whales whales_names.txt unsanitized_whales.txt corrected.txt
cat corrected.txt
18/01/18  9 Pygmy right whale
01/09/17 21 Southern right whale
16/02/18  4 Striped dolphin
02/07/17  4 Common dolphin
19/02/18  4 Blue whale
21/02/18 38 Dwarf sperm whale
14/06/17 29 Southern right whale
20/06/17  3 Spinner dolphin
22/07/17 34 Indo-Pacific humpbacked dolphin
20/03/18  7 Long-finned pilot whale
11/03/18 19 Short-finned pilot whale
24/09/17  5 Southern right whale

You may assume there are at most 256 different whale species.

When you think your program is working you can use autotest to run some simple automated tests:

1511 autotest sanitize_whales

When you are finished working on this exercise you must submit your work by running give:

give cs1511 wk09_sanitize_whales sanitize_whales.c

You must run give before Sunday 6 May 23:59:59 to obtain the marks for this lab exercise. Note, this is an individual exercise, the work you submit with give must be entirely your own.

When you are finished each exercises make sure you submit your work by running give.

You can run give multiple times. Only your last submission will be marked.

Don't submit any exercises you haven't attempted.

If you are working at home, you may find it more convenient to upload your work via give's web interface.

Remember you have until Sunday 6 May 23:59:59 to submit your work.

Automarking will be run several days after the submission deadline for the test. When complete you can view automarking here and you can view the the resulting mark via give's web interface

You can read more about lab assessment here