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 NAME     
 |  |  |  | quotestrdup, quoterunestrdup, unquotestrdup, unquoterunestrdup,
    quotestrfmt, quoterunestrfmt, quotefmtinstall, doquote, needsrcquote
    – quoted character strings 
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 SYNOPSIS     
 |  |  |  | #include <u.h> #include <libc.h> 
    
    
    char *quotestrdup(char *s) 
    
    
    Rune *quoterunestrdup(Rune *s) 
    
    
    char *unquotestrdup(char *s) 
    
    
    Rune *unquoterunestrdup(Rune *s) 
    
    
    int quotestrfmt(Fmt*) 
    
    
    int quoterunestrfmt(Fmt*) 
    
    
    void quotefmtinstall(void) 
    
    
    int (*doquote)(int c) 
    
    
    int needsrcquote(int c)
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 DESCRIPTION     
 |  |  |  | These routines manipulate character strings, either adding or
    removing quotes as necessary. In the quoted form, the strings
    are in the style of rc(1), with single quotes surrounding the
    string. Embedded single quotes are indicated by a doubled single
    quote. For instance, when quoted becomes
 The empty string is represented by two quotes, ''. 
    
    
    The first four functions act as variants of strdup (see strcat(3)).
    Each returns a freshly allocated copy of the string, created using
    malloc(3). Quotestrdup returns a quoted copy of s, while unquotestrdup
    returns a copy of s with the quotes evaluated. The rune versions
    of these functions do the same for strings (see runestrcat(3)).
    
    
    
    The string returned by quotestrdup or quoterunestrdup has the
    following properties:
 1.    If the original string s is empty, the returned string is ''.
 2.    If s contains no quotes, blanks, or control characters, the
    returned string is identical to s.
 3.    If s needs quotes to be added, the first character of the returned
    string will be a quote. For example, hello world becomes 'hello
    world' not hello' 'world. 
    
    
    The function pointer doquote is nil by default. If it is non-nil,
    characters are passed to that function to see if they should be
    quoted. This mechanism allows programs to specify that characters
    other than blanks, control characters, or quotes be quoted. Regardless
    of the return value of *doquote, blanks, control characters, and
    quotes are always
    quoted. Needsrcquote is provided as a doquote function that flags
    any character special to rc(1). 
    
    
    Quotestrfmt and quoterunestrfmt are print(3) formatting routines
    that produce quoted strings as output. They may be installed by
    hand, but quotefmtinstall installs them under the standard format
    characters q and Q. (They are not installed automatically.) If
    the format string includes the alternate format character #, for
    example %#q, the printed string will
    always be quoted; otherwise quotes will only be provided if necessary
    to avoid ambiguity. In <libc.h> there are #pragma statements so
    the compiler can type-check uses of %q and %Q in print(3) format
    strings.
 
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 SOURCE     
 SEE ALSO     
 BUGS     
 |  |  |  | Because it is provided by the format library, doquote is a preprocessor
    macro defined as fmtdoquote; see intro(3). 
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