


      STRING(3C)                  (UNIX 5.0)                 STRING(3C)



      NAME
           strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen,
           strchr, strrchr, strpbrk, strspn, strcspn, strtok - string
           operation


      SYNTAX
           #include <string.h>

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

           char *strncat (s1, s2, n)
           char *s1, *s2;
           int n;

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

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

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

           char *strncpy (s1, s2, n)
           char *s1, *s2;
           int n;

           int strlen (s)
           char *s;

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

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

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

           int strspn (s1, s2)
           char *s1, *s2;

           int strcspn (s1, s2)
           char *s1, *s2;

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

      DESCRIPTION



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      STRING(3C)                  (UNIX 5.0)                 STRING(3C)



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

           Strcat appends a copy of string s2 to the end of string s1.
           Strncat appends at most n characters.  Each returns a
           pointer to the null-terminated result.

           Strcmp compares its arguments and returns an integer less
           than, equal to, or greater than 0, according as s1 is
           lexicographically less than, equal to, or greater than s2.
           Strncmp makes the same comparison but looks at at most n
           characters.

           Strcpy copies string s2 to s1, 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.

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

           Strchr (strrchr) returns a pointer to the first (last)
           occurrence of character c in string s, or a NULL pointer if
           c does not occur in the string.  The null character
           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 (strcspn) returns the length of the initial segment
           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 on 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
           different from call to call.  When no token remains in s1, a
           NULL pointer is returned.



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      STRING(3C)                  (UNIX 5.0)                 STRING(3C)



      NOTE
           For user convenience, all these functions are declared in
           the optional <string.h> header file.

      BUGS
           Strcmp and strncmp use native character comparison, which is
           signed on PDP-11s, unsigned on other machines.

           Character movement is performed differently in different
           implementations.  Thus overlapping moves may yield
           surprises.












































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