diff options
Diffstat (limited to 'editors')
| -rw-r--r-- | editors/sed.c | 64 |
1 files changed, 42 insertions, 22 deletions
diff --git a/editors/sed.c b/editors/sed.c index a2df93165..87fc755eb 100644 --- a/editors/sed.c +++ b/editors/sed.c @@ -673,7 +673,7 @@ static void do_subst_w_backrefs(char *line, char *replace) /* go through the replacement string */ for (i = 0; replace[i]; i++) { - /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */ + /* if we find a backreference (\1, \2, etc.) print the backref'ed text */ if (replace[i] == '\\') { unsigned backref = replace[++i] - '0'; if (backref <= 9) { @@ -707,8 +707,10 @@ static void do_subst_w_backrefs(char *line, char *replace) static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p) { char *line = *line_p; - int altered = 0; unsigned match_count = 0; + bool altered = 0; + bool prev_match_empty = 1; + bool tried_at_eol = 0; regex_t *current_regex; current_regex = sed_cmd->sub_match; @@ -737,46 +739,64 @@ static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p) do { int i; - /* Work around bug in glibc regexec, demonstrated by: - * echo " a.b" | busybox sed 's [^ .]* x g' - * The match_count check is so not to break - * echo "hi" | busybox sed 's/^/!/g' - */ - if (!G.regmatch[0].rm_so && !G.regmatch[0].rm_eo && match_count) { - pipe_putc(*line++); - goto next; - } - match_count++; /* If we aren't interested in this match, output old line to - end of match and continue */ + * end of match and continue */ if (sed_cmd->which_match && (sed_cmd->which_match != match_count) ) { for (i = 0; i < G.regmatch[0].rm_eo; i++) pipe_putc(*line++); + /* Null match? Print one more char */ + if (G.regmatch[0].rm_so == i && *line) + pipe_putc(*line++); goto next; } - /* print everything before the match */ + /* Print everything before the match */ for (i = 0; i < G.regmatch[0].rm_so; i++) pipe_putc(line[i]); - /* then print the substitution string */ - do_subst_w_backrefs(line, sed_cmd->string); + /* Then print the substitution string, + * unless we just matched empty string after non-empty one. + * Example: string "cccd", pattern "c*", repl "R": + * result is "RdR", not "RRdR": first match "ccc", + * second is "" before "d", third is "" after "d". + * Second match is NOT replaced! + */ + if (prev_match_empty || i != 0) { + dbg("inserting replacement at %d in '%s'", i, line); + do_subst_w_backrefs(line, sed_cmd->string); + } else { + dbg("NOT inserting replacement at %d in '%s'", i, line); + } + + /* If matched string is empty (f.e. "c*" pattern), + * copy verbatim one char after it before attempting more matches + */ + prev_match_empty = (G.regmatch[0].rm_eo == i); + if (prev_match_empty && line[i]) { + pipe_putc(line[i]); + G.regmatch[0].rm_eo++; + } - /* advance past the match */ + /* Advance past the match */ + dbg("line += %d", G.regmatch[0].rm_eo); line += G.regmatch[0].rm_eo; - /* flag that something has changed */ - altered++; + /* Flag that something has changed */ + altered = 1; /* if we're not doing this globally, get out now */ if (sed_cmd->which_match != 0) break; next: - if (*line == '\0') - break; + /* Exit if we are at EOL and already tried matching at it */ + if (*line == '\0') { + if (tried_at_eol) + break; + tried_at_eol = 1; + } //maybe (G.regmatch[0].rm_eo ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL? } while (regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH); @@ -1127,7 +1147,7 @@ static void process_files(void) case 's': if (!do_subst_command(sed_cmd, &pattern_space)) break; - dbg("do_subst_command succeeeded:'%s'", pattern_space); + dbg("do_subst_command succeeded:'%s'", pattern_space); substituted |= 1; /* handle p option */ |