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sed 'y' command, simplify some other code

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This commit is contained in:
Glenn L McGrath 2003-03-30 08:02:18 +00:00
parent 0c51832b60
commit f01b46d7dd
1 changed files with 97 additions and 33 deletions
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130
editors/sed.c
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@ -97,9 +97,10 @@ typedef struct sed_cmd_s {
unsigned int sub_g:1; /* sed -e 's/foo/bar/g' (global) */
unsigned int sub_p:2; /* sed -e 's/foo/bar/p' (print substitution) */
/* GENERAL FIELDS */
char delimiter; /* The delimiter used to separate regexps */
/* TRANSLATE COMMAND */
char *translate;
/* GENERAL FIELDS */
/* the command */
char cmd; /* p,d,s (add more at your leisure :-) */
@ -148,23 +149,23 @@ static void destroy_cmd_strs(void)
}
#endif
/*
* index_of_next_unescaped_regexp_delim - walks left to right through a string
* beginning at a specified index and returns the index of the next regular
* expression delimiter (typically a forward * slash ('/')) not preceeded by
* a backslash ('\').
*/
static int index_of_next_unescaped_regexp_delim(const char delimiter, const char *str, int idx)
static int index_of_next_unescaped_regexp_delim(const char delimiter, const char *str)
{
int bracket = -1;
int escaped = 0;
int idx = 0;
char ch;
for ( ; (ch = str[idx]); idx++) {
if (bracket != -1) {
if (ch == ']' && !(bracket == idx - 1 ||
(bracket == idx - 2 && str[idx-1] == '^')))
(bracket == idx - 2 && str[idx-1] == '^')))
bracket = -1;
} else if (escaped)
escaped = 0;
@ -180,10 +181,43 @@ static int index_of_next_unescaped_regexp_delim(const char delimiter, const char
return -1;
}
static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
{
const char *cmdstr_ptr = cmdstr;
char delimiter;
int idx = 0;
/* verify that the 's' is followed by something. That something
* (typically a 'slash') is now our regexp delimiter... */
if (*cmdstr == '\0')
bb_error_msg_and_die("bad format in substitution expression");
else
delimiter = *cmdstr_ptr;
cmdstr_ptr++;
/* save the match string */
idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
if (idx == -1) {
bb_error_msg_and_die("bad format in substitution expression");
}
*match = bb_xstrndup(cmdstr_ptr, idx);
/* save the replacement string */
cmdstr_ptr += idx + 1;
idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
if (idx == -1) {
bb_error_msg_and_die("bad format in substitution expression");
}
*replace = bb_xstrndup(cmdstr_ptr, idx);
return((cmdstr_ptr - cmdstr) + idx);
}
/*
* returns the index in the string just past where the address ends.
*/
static int get_address(char *delimiter, char *my_str, int *linenum, regex_t **regex)
static int get_address(char *my_str, int *linenum, regex_t **regex)
{
int idx = 0;
if (isdigit(my_str[idx])) {
@ -198,13 +232,15 @@ static int get_address(char *delimiter, char *my_str, int *linenum, regex_t **re
}
else if (my_str[idx] == '/' || my_str[idx] == '\\') {
int idx_start = 1;
char delimiter;
*delimiter = '/';
delimiter = '/';
if (my_str[idx] == '\\') {
idx_start++;
*delimiter = my_str[++idx];
delimiter = my_str[++idx];
}
idx = index_of_next_unescaped_regexp_delim(*delimiter, my_str, ++idx);
idx++;
idx += index_of_next_unescaped_regexp_delim(delimiter, my_str + idx);
if (idx == -1) {
bb_error_msg_and_die("unterminated match expression");
}
@ -218,7 +254,6 @@ static int get_address(char *delimiter, char *my_str, int *linenum, regex_t **re
static int parse_subst_cmd(sed_cmd_t * const sed_cmd, const char *substr)
{
int oldidx;
int cflags = 0;
char *match;
int idx = 0;
@ -233,19 +268,7 @@ static int parse_subst_cmd(sed_cmd_t * const sed_cmd, const char *substr)
* (all three of the '/' slashes are mandatory)
*/
/* verify that the 's' is followed by something. That something
* (typically a 'slash') is now our regexp delimiter... */
if (substr[idx] == '\0')
bb_error_msg_and_die("bad format in substitution expression");
else
sed_cmd->delimiter=substr[idx];
/* save the match string */
oldidx = idx+1;
idx = index_of_next_unescaped_regexp_delim(sed_cmd->delimiter, substr, ++idx);
if (idx == -1)
bb_error_msg_and_die("bad format in substitution expression");
match = bb_xstrndup(substr + oldidx, idx - oldidx);
idx = parse_regex_delim(substr, &match, &sed_cmd->replace);
/* determine the number of back references in the match string */
/* Note: we compute this here rather than in the do_subst_command()
@ -259,13 +282,6 @@ static int parse_subst_cmd(sed_cmd_t * const sed_cmd, const char *substr)
sed_cmd->num_backrefs++;
}
/* save the replacement string */
oldidx = idx+1;
idx = index_of_next_unescaped_regexp_delim(sed_cmd->delimiter, substr, ++idx);
if (idx == -1)
bb_error_msg_and_die("bad format in substitution expression");
sed_cmd->replace = bb_xstrndup(substr + oldidx, idx - oldidx);
/* process the flags */
while (substr[++idx]) {
switch (substr[idx]) {
@ -297,6 +313,39 @@ out:
return idx;
}
static void replace_slash_n(char *string)
{
int i;
int remaining = strlen(string);
for (i = 0; string[i]; i++) {
if ((string[i] == '\\') && (string[i + 1] == 'n')) {
string[i] = '\n';
memmove(string + i + 1, string + i + 1, remaining - 1);
} else {
remaining--;
}
}
}
static int parse_translate_cmd(sed_cmd_t * const sed_cmd, const char *cmdstr)
{
char *match;
char *replace;
int idx;
int i;
idx = parse_regex_delim(cmdstr, &match, &replace);
replace_slash_n(match);
replace_slash_n(replace);
sed_cmd->translate = xcalloc(1, (strlen(match) + 1) * 2);
for (i = 0; (match[i] != 0) && (replace[i] != 0); i++) {
sed_cmd->translate[i * 2] = match[i];
sed_cmd->translate[(i * 2) + 1] = replace[i];
}
return(idx);
}
static int parse_edit_cmd(sed_cmd_t *sed_cmd, const char *editstr)
{
int i, j;
@ -417,6 +466,10 @@ static char *parse_cmd_str(sed_cmd_t * const sed_cmd, char *cmdstr)
strncpy(sed_cmd->label, cmdstr, length);
cmdstr += length;
}
/* translation command */
else if (sed_cmd->cmd == 'y') {
cmdstr += parse_translate_cmd(sed_cmd, cmdstr);
}
/* if it wasnt a single-letter command that takes no arguments
* then it must be an invalid command.
*/
@ -430,7 +483,6 @@ static char *parse_cmd_str(sed_cmd_t * const sed_cmd, char *cmdstr)
static char *add_cmd(sed_cmd_t *sed_cmd, char *cmdstr)
{
/* Skip over leading whitespace and semicolons */
cmdstr += strspn(cmdstr, semicolon_whitespace);
@ -452,13 +504,13 @@ static char *add_cmd(sed_cmd_t *sed_cmd, char *cmdstr)
*/
/* first part (if present) is an address: either a '$', a number or a /regex/ */
cmdstr += get_address(&(sed_cmd->delimiter), cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
/* second part (if present) will begin with a comma */
if (*cmdstr == ',') {
int idx;
cmdstr++;
idx = get_address(&(sed_cmd->delimiter), cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
if (idx == 0) {
bb_error_msg_and_die("get_address: no address found in string\n"
"\t(you probably didn't check the string you passed me)");
@ -911,6 +963,18 @@ static void process_file(FILE *file)
sed_cmd = branch_to(sed_cmd->label);
}
break;
case 'y': {
int i;
for (i = 0; line[i] != 0; i++) {
int j;
for (j = 0; sed_cmd->translate[j] ;j += 2) {
if (line[i] == sed_cmd->translate[j]) {
line[i] = sed_cmd->translate[j + 1];
}
}
}
}
break;
// case ':':
// break;
}