strdup() and strndup() functions in C/C++
The strdup() and strndup() functions are used to duplicate a string.
Syntax : char *strdup(const char *s);
This function returns a pointer to a null-terminated byte string, which is a duplicate of the string pointed to by s. The memory obtained is done dynamically using malloc and hence it can be freed using free().
It returns a pointer to the duplicated string s.
Below is the C implementation to show the use of strdup() function in C:
syntax: char *strndup(const char *s, size_t n);
This function is similar to strdup(), but copies at most n bytes.
Note: If s is longer than n, then only n bytes are copied, and a NULL (‘\0’) is added at the end.
Below is the C implementation to show the use of strndup() function in C:
Let us see the differences in a tabular form -:
|1.||It is used to return a pointer to a null-terminated byte string,||It is used to return a pointer to a null-terminated byte string|
|2.||Its syntax is -:
char * strdup( const char *str1 );
Its syntax is -:
char *strndup( const char *str, size_t size );
|3.||It is defined in <string.h> header file||It is defined in <string.h> header file|
|4.||It only take one parameter that is pointer to the null-terminated byte string to duplicate||
It takes two parameters that are -:
2. max number of bytes to copy from str
|5.||Its return value is pointer to the newly allocated string.||It returns a null pointer if an error occurred.|
Reference: Linux man(7)
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