quotestrdup, quoterunestrdup, unquotestrdup, unquoterunestrdup,
quotestrfmt, quoterunestrfmt, quotefmtinstall, doquote, needsrcquote
– quoted character strings|
char *quotestrdup(char *s)
Rune *quoterunestrdup(Rune *s)
char *unquotestrdup(char *s)
Rune *unquoterunestrdup(Rune *s)
int (*doquote)(int c)
int needsrcquote(int c)
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
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
Because it is provided by the format library, doquote is a preprocessor
macro defined as fmtdoquote; see intro(3).|