strdup

   NAME
    strdup  - duplicate a string using malloc


   SYNOPSIS
    char *s2 = strdup(s1);
    const char *s1;

   FUNCTION
    strdup malloc's enough space to hold s1 including the terminating
    nul and then copies s1 into this space, returning a pointer to
    the new string.  NULL is returned if space could not be allocated
    due to low memory conditions.

    free() may be used to free the returned string.  The amount
    malloc'd is (strlen(s1) + 1).

   NOTE
    strdup() is a non-standard function and may not exist in other
    C enviroments.

   EXAMPLE
    #include <stdio.h>
    #include <string.h>
    #include <assert.h>

    /*
     *  Modifying string constants (quoted strings) may not be entirely
     *  portable.  Normally one does not use strdup() to accomplish the
     *  following function but instead declares a char array statically
     *  initialized with the string, such as:
     *
     *  char FuBar[] = { "This is a test" };
     *
     *  Which can be modified in a portable fashion without having to
     *  duplicate the string.
     */

    main()
    {
        char *s1 = "this is a test";
        char *s2;

        s2 = strdup(s1);
        s2[0] = 'x';
        puts(s2);           /*  xhis is a test  */
        free(s2);

        s2 = strdup(s1);
        s2[1] = '0';
        puts(s2);           /*  t0is is a test  */
        free(s2);

        return(0);
    }

   INPUTS
    char *s1;   pointer to the string to duplicate

   RESULTS
    char *s2;   pointer to malloc'd space containing a duplicate
            of the string s1 or NULL if space could not be
            malloc'd.

   SEE ALSO
    malloc, free, strcpy, strlen