stuckisimon / progc

Exercises for PROGC module as part of computer science at zhaw

Hi there 👋

progc's Issues

Malloc check Pointer

There are unchecked calls to malloc.

E.g.:

progc/ss01-count-words-and-chars/src/main.c

Line 35 in 27a4b49

char *text = malloc(MAX_STRING_SIZE);

They must be checked using something like:

if (pointer == NULL) {
  return EXIT_FAILURE;
}

Standard Return Code

It is standard for CLIs and bash scripts to return non-zero return codes in case of error and 0 in case of success.

Therefore this snippet is not straightforward:

if (hasFailed == 1) {
  return 0;
}
return 1;

from ss04-word-sort/src/main.c

This does comply with the standard:

if (RETURN_CODE == 0) {
  // do sth in case of success
}
return RETURN_CODE;

One exception from this rule:
In case the name of the function is a predicate one can use "booleans" to indicate truthiness.

Add phony targets to makefile

Currently no Makefile uses phony targets. This especially affects the make doc command.

Therefore proper phony targets must be configured.

e.g.:

.PHONY: doc

Check out this nice documentation to see how and why phony targets are required: https://www.gnu.org/software/make/manual/html_node/Phony-Targets.html

Underscores shall be used to separate words in names

According to the code style guide:

Underscores shall be used to separate words in names e.g. count_active_users()

Currently the method names use camel case.

Buffer Overflow issues when using scanf

Currently usages of scanf are prone to buffer overflow which is a potential security risk.

See these two occurences:

progc/ss03-notenstatistik/src/main.c

Line 32 in d60e5b9

scanf("%d", minPoints);

progc/ss04-word-sort/src/main.c

Line 57 in d60e5b9

(void) scanf("%s", word);

For informations about how to fix this, have a look at this stackoverflow question: https://stackoverflow.com/questions/12306591/read-no-more-than-size-of-string-with-scanf

Doxyfile reference

Currently Makefiles reference a non-existing Doxyfile. This obviously does not work on machines with a different folder structure.
Doxyfile must be at the repository root.

progc/ss01-fahrenheit-to-celcius/Makefile

Line 34 in 27a4b49

doxygen ../../Doxyfile > /dev/null

Furthermore all references must be updated.

Use safe string operations

Currently there are usages of unchecked string operations.

E.g.

progc/ss04-word-sort/src/main.c

Line 25 in 3ae64b8

return strcmp (*(const char **) a, *(const char **) b);

See this stackoverflow question.

One should therefore use
strncmp instead of strcmp
strncpy instead of strcpy
and so on...