Regex

Forked from tiny-regex-c

Fully refactored Regex library. Fixed all issues and added lazy operators. Also improved Regex compilation and removed static allocation. Code coverage with Perl tests.

Features

• Small and portable
• Designed for small embedded applications
• Provides matching characters length and first match occurrence index
• Compiled with (MinGW.org GCC-6.3.0-1) 6.3.0

  > gcc -Os -c Regex.c
  > size Regex.o
     text    data     bss     dec     hex filename
     3732       0       0    3732    125c Regex.o
      
  

Add as CPM project dependency

How to add CPM to the project, check the link

CPMAddPackage(
        NAME Regex
        GITHUB_REPOSITORY ximtech/Regex
        GIT_TAG origin/main)

target_link_libraries(${PROJECT_NAME} Regex)

add_executable(${PROJECT_NAME}.elf ${SOURCES} ${LINKER_SCRIPT})
# For Clion STM32 plugin generated Cmake use 
target_link_libraries(${PROJECT_NAME}.elf Regex)

Supported regex-operators

The following features / regex-operators are supported by this library.

• . Dot, matches any character
• ^ Start anchor, matches beginning of string
• $ End anchor, matches end of string
• * Asterisk, match zero or more (greedy)
• + Plus, match one or more (greedy)
• *? Asterisk, match zero or more (lazy)
• +? Plus, match one or more (lazy)
• ? Question, match zero or one (lazy)
• {m,n} Quantifier, match min. 'm' and max. 'n' (greedy)
• {m} Exactly 'm'
• {m,} Match min 'm' and max.
• [abc] Character class, match if one of {'a', 'b', 'c'}
• [^abc] Inverted class, regexMatch if NOT one of {'a', 'b', 'c'}
• [a-zA-Z] Character ranges, the character set of the ranges { a-z | A-Z }
• \s Whitespace, \t \f \r \n \v and spaces
• \S Non-whitespace
• \w Alphanumeric, [a-zA-Z0-9_]
• \W Non-alphanumeric
• \d Digits, [0-9]
• \D Non-digits

Usage

Regex regex;
regexCompile(&regex, "[Hh]ello [Ww]orld\\s*[!]?");
if (!regex.isPatternValid) {
    printf("Error: %s\n", regex.errorMessage);
    return 1;
}

Matcher matcher = regexMatch(&regex, "ahem.. 'hello world !' ..");
printf("Is found: %s\n", matcher.isFound ? "Yes" : "No");
printf("At index: %d\n", matcher.foundAtIndex);
printf("Length: %d\n", matcher.matchLength);