C Library Functions string(3C)
NAME
string, strcasecmp, strncasecmp, strcat, strncat, strchr,
strrchr, strcmp, strncmp, strcpy, strncpy, strcspn, strspn,
strdup, strlen, strpbrk, strstr, strtok, strtok_r, - string
operations
SYNOPSIS
#include <strings.h>
#include <string.h>
/...snipp - bort med saker som inte berör strtok.../
char *strtok(char *s1, const char *s2);
char *strtok_r(char *s1, const char *s2, char **lasts);
DESCRIPTION
The arguments s, s1, and s2 point to strings (arrays of
characters terminated by a null character). The strcat(),
strncat(), strcpy(), strncpy(), strtok(), and strtok_r()
functions all alter their first argument. These functions do
not check for overflow of the array pointed to by the first
argument.
/...snipp - bort med lite mer.../
strtok()
The strtok() function can be used to break the string
pointed to by s1 into a sequence of tokens, each of which is
delimited by one or more characters from the string pointed
to by s2. The strtok() function 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 being 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.
strtok_r()
The strtok_r() function has the same functionality as
strtok() except that a pointer to a string placeholder lasts
must be supplied by the caller. The lasts pointer is to
keep track of the next substring in which to search for the
next token.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| MT-Level | See NOTES below. |
|_____________________________|_____________________________|
SEE ALSO
malloc(3C), setlocale(3C), strxfrm(3C), attributes(5)
NOTES
The strtok_r() function is as proposed in the POSIX.4a Draft
#6 document, and is subject to change to be compliant to the
standard when it is accepted.
When compiling multithreaded applications, the _REENTRANT
flag must be defined on the compile line. This flag should
only be used in multithreaded applications.
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.
The strcasecmp(), strcat(), strchr(), strcmp(), strcpy(),
strcspn(), strdup(), strlen(), strncasecmp(),
strncat(),strncmp(), strncpy(), strpbrk(),strrchr(),
strspn(), and strstr() functions are MT-Safe in mul-
tithreaded applications.
The strtok() function is Unsafe in multithreaded applica-
tions. The strtok_r() function should be used instead.
|