string(3C)           COMPATIBILITY FUNCTIONS           string(3C)



NAME
     string: strcat, strdup, strncat,  strcmp,  strncmp,  strcpy,
     strncpy,  strlen, strchr, strrchr, strpbrk, strspn, strcspn,
     strtok, strstr - string operations

SYNOPSIS
     #include <string.h>

     char *strcat (char *s1, const char *s2);

     char *strdup (const char *s1);

     char *strncat (char *s1, const char *s2, size_t n);

     int strcmp (const char *s1, const char *s2);

     int strncmp (const char *s1, const char *s2, size_t n);

     char *strcpy (char *s1, const char *s2);

     char *strncpy (char *s1, const char *s2, size_t n);

     size_t strlen (const char *s);

     char *strchr (const char *s, int c);

     char *strrchr (const char *s, int c);

     char *strpbrk (const char *s1, const char *s2);

     size_t strspn (const char *s1, const char *s2);

     size_t strcspn (const char *s1, const char *s2);

     char *strtok (char *s1, const char *s2);

     char *strstr (const char *s1, const char *s2);

DESCRIPTION
     The arguments s, s1, and s2  point  to  strings  (arrays  of
     characters  terminated  by a null character).  The functions
     strcat, strncat, strcpy, strncpy, and strtok.  all alter s1.
     These  functions  do  not  check  for  overflow of the array
     pointed to by s1.

     strcat appends a copy of string s2, including the  terminat-
     ing  null  character,  to  the  end  of  string s1.  strncat
     appends at most n characters.  Each returns a pointer to the
     null-terminated  result.   The initial character of s2 over-
     rides the null character at the end of s1.





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string(3C)           COMPATIBILITY FUNCTIONS           string(3C)



     strcmp compares its arguments and returns  an  integer  less
     than,  equal to, or greater than 0, based upon whether s1 is
     lexicographically less than, equal to, or greater  than  s2.
     strncmp  makes  the  same  comparison but looks at at most n
     characters.  Characters following a null character  are  not
     compared.

     strcpy copies string s2 to s1 including the terminating null
     character,  stopping  after  the  null  character  has  been
     copied.  strncpy copies exactly n characters, truncating  s2
     or  adding  null  characters to s1 if necessary.  The result
     will not be null-terminated if the length  of  s2  is  n  or
     more.  Each function returns s1.

     strdup returns a pointer to a new string which is  a  dupli-
     cate  of  the string pointed to by s1. The space for the new
     string is obtained using malloc(3C).  If the new string  can
     not be created, a NULL pointer is returned.

     strlen returns the number of characters in s, not  including
     the terminating null character.

     strchr (or strrchr) returns a pointer to  the  first  (last)
     occurrence of c (converted to a char) in string s, or a NULL
     pointer if c does not occur in the string.  The null charac-
     ter  terminating  a  string  is considered to be part of the
     string.

     strpbrk returns a pointer to the first occurrence in  string
     s1  of any character from string s2, or a NULL pointer if no
     character from s2 exists in s1.

     strspn (or strcspn) returns the length of the  initial  seg-
     ment of string s1 which consists entirely of characters from
     (not from) string s2.

     strtok considers the string s1 to consist of a  sequence  of
     zero  or  more text tokens separated by spans of one or more
     characters from the separator string  s2.   The  first  call
     (with  pointer  s1 specified) returns a pointer to the first
     character of the first token, and will have written  a  null
     character  into s1 immediately following the returned token.
     The function keeps track  of  its  position  in  the  string
     between separate calls, so that subsequent calls (which must
     be made with the first argument a NULL  pointer)  will  work
     through  the string s1 immediately following that token.  In
     this way subsequent calls will work through  the  string  s1
     until no tokens remain.  The separator string s2 may be dif-
     ferent from call to call.  When no token remains  in  s1,  a
     NULL pointer is returned.





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string(3C)           COMPATIBILITY FUNCTIONS           string(3C)



     strstr locates the first occurrence  in  string  s1  of  the
     sequence of characters (excluding the terminating null char-
     acter) in string  s2.   strstr  returns  a  pointer  to  the
     located  string,  or  a  null  pointer  if the string is not
     found. If s2 points to a string with zero length (i.e.,  the
     string ""), the function returns s1.

SEE ALSO
     malloc(3C), setlocale(3C), strxfrm(3C).

NOTES
     All of these functions assume the default locale ``C.''  For
     some  locales,  strxfrm  should  be  applied  to the strings
     before they are passed to the functions.









































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