GuiarStr is a comprehensive, professional-grade string manipulation library for C programmers.
While C has very basic string support, GuiarStr provides a rich set of modern string operations with:

• Dynamic strings
• Unicode/UTF-8 support
• Memory safety
• Efficient performance

Perfect for embedded systems to complex multilingual software — without external dependencies.

| Function | Description |

| guiarstr_trim | Removes leading and trailing whitespace. |

| guiarstr_strip | Removes specified characters from both ends. |

| guiarstr_tolower / guiarstr_toupper | Converts string to lowercase/uppercase (in-place). |

| guiarstr_reverse | Reverses a string (UTF-8 safe). |

| guiarstr_replace | Replaces all occurrences of a substring.

| guiarstr_replace_n | Replaces with a limit on replacements.

| guiarstr_replace_char | Replaces all occurrences of a character. | guiarstr_remove_chars | Removes all specified characters.|

• guiarstr_starts_with / guiarstr_ends_with – Prefix/suffix checking.
• guiarstr_starts_withi / guiarstr_endswithi – Case-insensitive variants.
• guiarstr_contains – Checks if a string contains a substring.
• guiarstr_count – Counts occurrences of a substring.
• guiarstr_find / guiarstr_rfind – Find substring positions.
• guiarstr_find_char / guiarstr_rfind_char – Find character positions.
• guiarstr_find_any / guiarstr_find_not_any – Advanced character search.

• guiarstr_split – Splits by character delimiter.
• guiarstr_split_str – Splits by string delimiter.
• guiarstr_split_any – Splits by any of multiple delimiters.
• guiarstr_split_lines – Splits by line endings (handles \n, \r\n).
• guiarstr_join – Joins string array with separator.
• guiarstr_join_views – Joins string views efficiently.

• guiarstr_create – Creates a dynamic string.
• guiarstr_append – Appends to a dynamic string.
• guiarstr_insert – Inserts at a specific position.
• guiarstr_remove – Removes a range of characters.
• guiarstr_reserve – Pre-allocates memory.
• guiarstr_resize – Resizes with fill character.
• guiarstr_shrink_to_fit – Optimizes memory usage.

• guiarstr_builder_create – Creates an efficient string builder.
• guiarstr_builder_append – Appends strings efficiently.
• guiarstr_builder_append_fmt – Appends formatted strings.
• guiarstr_builder_build – Builds the final string.

• guiarstr_utf8_len – Gets UTF-8 character count.
• guiarstr_utf8_char_len – Gets byte length of a UTF-8 character.
• guiarstr_utf8_byte_pos – Converts character position to byte position.
• guiarstr_utf8_validate – Validates UTF-8 sequences.
• guiarstr_utf8_width – Gets display width for monospace fonts.
• guiarstr_utf8_substring – Extracts UTF-8 substring.

✅ Handles emojis, Arabic, and all Unicode characters correctly.

• guiarstr_to_int / guiarstr_from_int
• guiarstr_to_double / guiarstr_from_double
• guiarstr_to_long / guiarstr_from_long
  ✔ Includes error handling.

• guiarstr_printf – Creates formatted strings.
• guiarstr_append_printf – Appends formatted strings to dynamic strings.

• guiarstr_read_file – Reads entire file into a string.
• guiarstr_write_file – Writes string content to file.

• Comprehensive error codes with descriptive messages.
• All functions return error status for safe operation.
• guiarstr_error_message – Gets human-readable error descriptions.

• Fully UTF-8 aware operations.
• Works perfectly for multilingual apps and terminal-based UIs.
• Supports byte-level and character-level manipulation.

make            # Builds static lib (libguiarstr.a) + shared lib (libguiarstr.so)
make test       # Runs the test suite
make example    # Builds usage demo

make install PREFIX=$HOME/.local

• guiarstr.h → $PREFIX/include

• libguiarstr.a and libguiarstr.so → $PREFIX/lib

• guiarstr.pc → $PREFIX/lib/pkgconfig

mkdir build && cd build
cmake ..
make
sudo make install

Basic Operations :

#include <stdio.h>
#include "guiarstr.h"

int main() {
    char text[] = "  Hello World  ";
    printf("Trimmed: '%s'\n", guiarstr_trim(text));

    size_t count;
    char** parts = guiarstr_split_str("oneXYZtwoXYZthree", "XYZ", &count);
    for (size_t i = 0; i < count; ++i) {
        printf("Part %zu: %s\n", i + 1, parts[i]);
    }
    guiarstr_split_free(parts, count);

    char* reversed = guiarstr_reverse("okba😊dev");
    printf("Reversed: %s\n", reversed);
    free(reversed);
}

#include "guiarstr.h"

int main() {
    GuiarStr* str = guiarstr_create("Hello");
    guiarstr_append(str, " World");
    guiarstr_append_char(str, '!');
    guiarstr_insert(str, 5, " there");

    printf("Dynamic string: '%s'\n", str->data);

    guiarstr_free(str);
}

#include "guiarstr.h"

int main() {
    GuiarStrBuilder* builder = guiarstr_builder_create(16);
    guiarstr_builder_append(builder, "The answer is: ");
    guiarstr_builder_append_fmt(builder, "%d", 42);

    GuiarStr* result = guiarstr_builder_build(builder);
    printf("Built: '%s'\n", result->data);

    guiarstr_free(result);
    guiarstr_builder_free(builder);
}

#include "guiarstr.h"

int main() {
    const char* text = "مرحبا 😊";
    printf("UTF-8 length: %zu characters\n", guiarstr_utf8_len(text));
    printf("Byte length: %zu bytes\n", strlen(text));
    printf("Display width: %zu columns\n", guiarstr_utf8_width(text));

    char* substr = guiarstr_utf8_substring(text, 2, 2);
    printf("Substring [2:4]: '%s'\n", substr);
    free(substr);
}

gcc main.c $(pkg-config --cflags --libs guiarstr) -o app

export PKG_CONFIG_PATH=$HOME/.local/lib/pkgconfig

guiarstr/
├── include/              # Public headers
│   └── guiarstr.h
├── src/                  # Implementation
│   └── guiarstr.c
├── tests/                # Tests
│   └── main.c
├── examples/             # Example programs
│   └── usage.c
├── assets/               # Images
│   └── build_and_test.png
├── CMakeLists.txt
├── guiarstr.pc
├── guiarstr.pc.in
├── Makefile
├── README.md
├── CHANGELOG.md
└── LICENSE

Contributions are welcome! Please feel free to submit a Pull Request.

Fork the repository Create your feature branch

(git checkout -b feature/amazing-feature)

Commit your changes

(git commit -m 'Add some amazing feature')

Push to the branch

(git push origin feature/amazing-feature)

Open a Pull Request.

👤 Name: GUIAR OQBA

📧 Email: [email protected]

🌐 ORCID: 0009-0008-1629-0002

💼 LinkedIn: guiar-oqba

💻 GitHub: okba14

📚 Zenodo: 15786076

📝 Hashnode: @okba

✈️ Telegram: @okba_elkantara

📱 Phone: +2136-71-36-04-38

© 2025 GUIAR OQBA 🇩🇿
Made with 💻 & ❤️ from Algeria

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