1index(3C)                Standard C Library Functions                index(3C)
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NAME

6       index, rindex - string operations
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SYNOPSIS

9       #include <strings.h>
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11       char *index(const char *s, int c);
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14       char *rindex(const char *s, int c);
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DESCRIPTION

18       The index() and rindex() functions operate on null-terminated strings.
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21       The index() function returns a pointer to the first occurrence of char‐
22       acter c in string s.
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25       The rindex() function returns a pointer to the last occurrence of char‐
26       acter c in string s.
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29       Both index() and  rindex() return a null pointer if c does not occur in
30       the string. The null character terminating a string is considered to be
31       part of the string.
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USAGE

34       On  most  modern  computer  systems,  you can not use a null pointer to
35       indicate a null string.  A null pointer is an error and results  in  an
36       abort  of the program.  If you wish to indicate a null string, you must
37       use a pointer that points to an explicit null string.  On some machines
38       and  with  some  implementations  of the C programming language, a null
39       pointer, if dereferenced, would yield  a  null  string.   Though  often
40       used,  this  practice  is not always portable. Programmers using a null
41       pointer to represent an empty string should be aware of this  portabil‐
42       ity  issue.   Even  on machines where dereferencing a null pointer does
43       not cause an abort of the program, it does not necessarily yield a null
44       string.
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ATTRIBUTES

47       See attributes(5) for descriptions of the following attributes:
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52       ┌─────────────────────────────┬─────────────────────────────┐
53       │ATTRIBUTE TYPE               │ATTRIBUTE VALUE              │
54       ├─────────────────────────────┼─────────────────────────────┤
55       │Interface Stability          │Standard                     │
56       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

59       bstring(3C), malloc(3C), string(3C), attributes(5), standards(5)
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63SunOS 5.11                        24 Jul 2002                        index(3C)
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