sf_sed(3) BSD Library Functions Manual sf_sed(3)NAME
sed_compile, sed_exec, sed_free — string editor
SYNOPSIS
#include <strfunc.h>
sed_t *
sed_compile(char *expr);
char *
sed_exec(sed_t *se, char *string);
svect *
sed_results(sed_t *se);
void
sed_free(sed_t *se);
DESCRIPTION
These routines implement a subset of sed(1) or Perl's s///, y/// and //
functionality.
You must compule your expression with sed_compile() in order to evaluate
it later. Once compiled, it can be evaluated multiple times. See the
EXPRESSIONS block to know about expressions semantics.
sed_free() used to destroy the compiled structure and free the allocated
memory.
sed_exec() takes the source string and transforms it according to the
compiled rules. Resulting string stored in the internal buffer within
the specified sed_t structure.
sed_results() May be invoked multiple times after sed_exec() to obtain
last match results. An 'r' flag should be specified within the expression
string.
EXPRESSIONS
Currently, this library supports two types of string transformations and
one type of string match.
Substitutions
Expressions of this type are defined in the following BNF:
<delim> := '/' | <other_character>
<regex> := <regular_expression, re_format(7)>
<to> := <string>
<flags> := *( 'g' | 'i' | 'e' | 'r' | 'm' | 'n' )
<expr> := s <delim> <regex> <delim> <to> <delim> <flags>
Refer to sed(1) manual page to know other details.
Table lookup
<delim> := '/' | <other_character>
<flags> := *( 'i' )
<expr> := y <delim> <string> <delim> <string> <delim> <flags>
String match
<delim> := '/' | <other_character>
<flags> := *( 'i' | 'r' | 'm' | 'n' )
<reply> := <string>
<expr> := <delim> <string> <delim> [ <reply> <delim>] <flags>
In the last case, if string does not match, sed_exec() will return a NULL
pointer, <reply> otherwise. s/// and y/// functions will never return a
NULL pointer.
Flags are common to those transformations.
'i' case-insensitive matches.
'e' compile in extended mode (REG_EXTENDED).
'g' Make the substitution for all non-overlapping matches of
the regular expression, not just the first one.
'r' Remember last match results to allow use of sed_results().
'm' Compile for newline-sensitive matching (REG_NEWLINE).
'n' Don't include zero regexec(3) match (a whole substring)
into results list.
EXAMPLE
void main() {
sed_t *se1;
sed_t *se2;
sed_t *se3;
char *r1, *r2, r3;
/* Compile expressions */
se1 = sed_compile("s/(tree) (apple)/\\2 \\1/igr");
se2 = sed_compile("y/abc/AbC/i");
se3 = sed_compile("/apple/i");
r1 = sed_exec(se1, "Tree Apple");
r2 = sed_exec(se2, "abcabc");
r3 = sed_exec(se3, "another apple tree");
/*
** This will produce:
** "Apple Tree\nAbCAbC\n1\n"
*/
printf("%s\n%s\n%d\n", r1, r2, r3?1:0);
/*
** This will produce:
** "[Tree Apple], [Tree], [Apple]\n"
*/
printf("[%s]\n", sjoin(sed_results(se1), "], ["));
/* Free the resources */
sed_free(se1);
sed_free(se2);
sed_free(se3);
};
SEE ALSOstrfunc(3).
AUTHORS
Lev Walkin <vlm@lionet.info>
BSD December 4, 2000 BSD
