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 NAME     
 |  |  |  | strcat, strncat, strcmp, strncmp, cistrcmp, cistrncmp, strcpy,
    strncpy, strecpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn,
    strtok, strdup, strstr, cistrstr – string operations 
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 SYNOPSIS     
 |  |  |  | #include <u.h> #include <libc.h> 
    
    
    char* strcat(char *s1, char *s2) 
    
    
    char* strncat(char *s1, char *s2, long n) 
    
    
    int    strcmp(char *s1, char *s2) 
    
    
    int    strncmp(char *s1, char *s2, long n) 
    
    
    int    cistrcmp(char *s1, char *s2) 
    
    
    int    cistrncmp(char *s1, char *s2, long n) 
    
    
    char* strcpy(char *s1, char *s2) 
    
    
    char* strecpy(char *s1, char *es1, char *s2) 
    
    
    char* strncpy(char *s1, char *s2, long n) 
    
    
    long    strlen(char *s) 
    
    
    char* strchr(char *s, char c) 
    
    
    char* strrchr(char *s, char c) 
    
    
    char* strpbrk(char *s1, char *s2) 
    
    
    long    strspn(char *s1, char *s2) 
    
    
    long    strcspn(char *s1, char *s2) 
    
    
    char* strtok(char *s1, char *s2) 
    
    
    char* strdup(char *s) 
    
    
    char* strstr(char *s1, char *s2) 
    
    
    char* cistrstr(char *s1, char *s2)
 
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 DESCRIPTION     
 |  |  |  | The arguments s1, s2 and s point to null-terminated strings. The
    functions strcat, strncat, strcpy, strecpy, and strncpy all alter
    s1. Strcat and strcpy 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 bytes. 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 examines at most n bytes. Cistrcmp and cistrncmp
    ignore ASCII case distinctions when comparing strings. The comparisons
    are made with
    unsigned bytes. 
    
    
    Strcpy copies string s2 to s1, stopping after the null byte has
    been copied. Strncpy copies exactly n bytes, truncating s2 or
    adding null bytes to s1 if necessary. The result will not be null-terminated
    if the length of s2 is n or more. Each function returns s1. 
    
    
    Strecpy copies bytes until a null byte has been copied, but writes
    no bytes beyond es1. If any bytes are copied, s1 is terminated
    by a null byte, and a pointer to that byte is returned. Otherwise,
    the original s1 is returned. 
    
    
    Strlen returns the number of bytes in s, not including the terminating
    null byte. 
    
    
    Strchr (strrchr) returns a pointer to the first (last) occurrence
    of byte c in string s, or 0 if c does not occur in the string.
    The null byte terminating a string is considered to be part of
    the string. 
    
    
    Strpbrk returns a pointer to the first occurrence in string s1
    of any byte from string s2, 0 if no byte from s2 exists in s1.
    
    
    
    Strspn (strcspn) returns the length of the initial segment of
    string s1 which consists entirely of bytes 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 bytes from
    the separator string s2. The first call, with pointer s1 specified,
    returns a pointer to the first byte of the first token, and will
    have written a null byte into s1 immediately following the returned
    token. The function keeps track of its
    position in the string between separate calls; subsequent calls,
    signified by s1 being 0, will work through the string s1 immediately
    following that token. The separator string s2 may be different
    from call to call. When no token remains in s1, 0 is returned.
    
    
    
    Strdup returns a pointer to a distinct copy of the null-terminated
    string s in space obtained from malloc(3) or 0 if no space can
    be obtained. 
    
    
    Strstr returns a pointer to the first occurrence of s2 as a substring
    of s1, or 0 if there is none. If s2 is the null string, strstr
    returns s1. Cistrstr operates analogously, but ignores ASCII case
    differences when comparing strings. 
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 SOURCE     
 SEE ALSO    
 BUGS     
 |  |  |  | These routines know nothing about UTF. Use the routines in rune(3)
    as appropriate. Note, however, that the definition of UTF guarantees
    that strcmp compares UTF strings correctly. 
    
    
    The outcome of overlapping moves varies among implementations. 
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