FreeBSD Manual Pages
std::strtok(3) C++ Standard Libary std::strtok(3) NAME std::strtok - std::strtok Synopsis Defined in header <cstring> char* strtok( char* str, const char* delim ); Finds the next token in a null-terminated byte string pointed to by str. The separator characters are identified by null-terminated byte string pointed to by delim. This function is designed to be called multiple times to obtain suc- cessive tokens from the same string. * If str is not a null pointer, the call is treated as the first call to strtok for this particular string. The function searches for the first character which is not contained in delim. * If no such character was found, there are no tokens in str at all, and the function returns a null pointer. * If such character was found, it is the beginning of the token. The function then searches from that point on for the first character that is contained in delim. * If no such character was found, str has only one token, and the future calls to strtok will return a null pointer * If such character was found, it is re- placed by the null character '\0' and the pointer to the fol- lowing character is stored in a static location for subse- quent invocations. * The function then returns the pointer to the beginning of the token * If str is a null pointer, the call is treated as a subsequent call to strtok: the function continues from where it left in previous invoca- tion. The behavior is the same as if the previously stored pointer is passed as str. Parameters str - pointer to the null-terminated byte string to tokenize delim - pointer to the null-terminated byte string identifying de- limiters Return value Pointer to the beginning of the next token or a nullptr if there are no more tokens. Notes This function is destructive: it writes the '\0' characters in the elements of the string str. In particular, a string literal cannot be used as the first argument of std::strtok. Each call to this function modifies a static variable: is not thread safe. Unlike most other tokenizers, the delimiters in std::strtok can be different for each subsequent token, and can even depend on the contents of the previous tokens. Example // Run this code #include <cstring> #include <iostream> #include <iomanip> int main() { char input[] = "one + two * (three - four)!"; const char* delimiters = "! +- (*)"; char *token = std::strtok(input, delimiters); while (token) { std::cout << std::quoted(token) << ' '; token = std::strtok(nullptr, delimiters); } std::cout << "\nContents of the input string now:\n\""; for (std::size_t n = 0; n < sizeof input; ++n) { if (const char c = input[n]; c != '\0') std::cout << c; else std::cout << "\\0"; } std::cout << "\"\n"; } Output: "one" "two" "three" "four" Contents of the input string now: "one\0+ two\0* (three\0- four\0!\0" See also finds the first location of any character from a set of strpbrk separators (function) returns the length of the maximum initial segment that consists strcspn of only the characters not found in another byte string (function) returns the length of the maximum initial segment that consists strspn of only the characters found in another byte string (function) ranges::split_view a view over the subranges obtained from splitting another view views::split using a delimiter (C++20) (class template) (range adaptor object) http://cppreference.com 2022.07.31 std::strtok(3)
NAME | Synopsis | Parameters | Return value | Notes | Example | Output: | See also
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=std::strtok&sektion=3&manpath=FreeBSD+Ports+15.0>