yaowenqiang / collections-c

A library of generic data structures.

Collections-C

A library of generic data structures including a list, array, hashtable, deque etc..

• Examples
• Building and Installing
• Using the library
• Contributing

Examples

Check the documentation page for mode detailed examples. (This is still in progress). The source of the documentation can be found here.

HashTable

// Crate a new table
CC_HashTable *table;
if (cc_hashtable_new(&table) != CC_OK) {
    // something went wrong
    ...
}
// Add key-value pair
if (cc_hashtable_add(table, "some_key", "some_value") != CC_OK) {
    // something went wrong
    ...
}
// Retrieve a value associated with a key
char *value;
if (cc_hashtable_get(table, "some_key", (void*) &value) == CC_OK)
    printf("%s", value);

// Remove a key
cc_hashtable_remove(table, "foo", NULL);
cc_hashtable_destroy(table);

Array (dynamic array)

// Create a new array
CC_Array *ar;
if (cc_array_new(&ar) != CC_OK) {
    // something went wrong
    ...
}
// Add an element
enum cc_stat status = cc_array_add(ar, "foo");
if (status == CC_OK) {
    ...
} else if (status == CC_ERR_ALLOC) {
    ...
} else {
    ...
}
// Retrieve a value
char *foo;
cc_array_get_at(ar, 0, (void*) &foo);

// Remove a value
char *removed;
cc_array_remove_at(ar, 0, (void*) &removed);

cc_array_destroy(ar);

Building and Installation

Dependencies

• C compiler (gcc, clang, etc...)
• cmake (>= 3.5)
• [testing only] cpputest (>=3.8)
• pkg-config

These packages can usually be installed through your distributions package manager.

Building on windows requires MinGW which provides all the tools needed to build the project.

Building the project

To build the project, we first need to create a separate build directory:

mkdir build

Now that we've created our build directory (assuming it's created in the projct root), we can cd into it and run cmake and pass the parent directory path to it, which is where the CMakeLists.txt file is located:

cd build
cmake ..

Once cmake is done generating makefiles, we can build the library by running make inside our build directory:

make

This will build both the static and the dynamic library.

Running tests

make test

Running individual tests

make build
build/test/array_test -c -v

Installing

To install the library run:

sudo make install

By default the libraries and headers will be installed in /usr/local/lib/ and /usr/local/include directories.

You have to make the system's runtime aware of the location of the new library to be able to run dynamically linked applications. This might be as simple as running the following command if your /etc/ld.so.conf contains the install directory.

Note: macOS doesn't support ldconfig.

sudo ldconfig

Using Collections-C in your programs

A simple program

If we already built and installed the library, we can write a simple hello world program and save it to a file named hello.c:

#include <stdio.h>
#include <collectc/cc_array.h>

int main(int argc, char **argv) {
    // Create a new array
    CC_Array *ar;
    cc_array_new(&ar);

    // Add a string to the array
    cc_array_add(ar, "Hello World!\n");

    // Retreive the string and print it
    char *str;
    cc_array_get_at(ar, 0, (void*) &str);
    printf("%s", str);

    return 0;
}

Now we need to compile and link our program. Since make builds both the static and the dynamic library we can choose which one we wish to link into our program.

Linking statically

If we wish to statically link the library to our program we can pass the -static flag to the compiler

Note: On macOS, the -static flag is not very friendly (it requires that all the libraries are statically linked). So we can replace -static -lcollectc with the full path to the static library. Which is /usr/local/lib/libcollectc.a by default.

gcc hello.c -static -lcollectc -o hello

or similarly when compiling with clang:

clang hello.c -static -lcollectc -o hello

This will link the library by copying it into the executable. We can use this option if we don't wish to have Collections-C as a runtime dependency, however this comes at the expense of generating a larger executable.

Linking dynamically

We can also choose to link with the library dynamically at runtime. This is the default behaviour if ommit the -static compiler flag:

gcc hello.c -lcollectc -o hello

or with clang:

clang hello.c -lcollectc -o hello

Linking dynamically produces a smaller executable, but requires libcollectc.so to be present on every system on which the program is going to be executed.

Linking problems

Sometimes the compiler may have trouble finding the library or the headers. This is usually because it's looking for them in the wrong directory, which may happen if the library or the headers or both are installed in a non-standard directory or not installed at all.

If this is the case, we can explicitly tell the compiler where to look for them by passing the -I[path to headers] and -L[path to libraries] options:

gcc hello.c `pkg-config --cflags --libs collectionc` -o hello

Running the program

If everything went well with the compilation we can run the executable:

./hello

and it should print Hello, World! to the console.

Contributing

Contributions are welcome.

If you have a feature request, or have found a bug, feel free to open a new issue. If you wish to contribute code, see CONTRIBUTING.md for more details.