diff options
Diffstat (limited to 'readline/histexpand.c')
| -rw-r--r-- | readline/histexpand.c | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/readline/histexpand.c b/readline/histexpand.c new file mode 100644 index 0000000..0dc179a --- /dev/null +++ b/readline/histexpand.c @@ -0,0 +1,1355 @@ +/* histexpand.c -- history expansion. */ + +/* Copyright (C) 1989, 1992 Free Software Foundation, Inc. + + This file contains the GNU History Library (the Library), a set of + routines for managing the text of previously typed lines. + + The Library is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 1, or (at your option) + any later version. + + The Library is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + The GNU General Public License is often shipped with GNU software, and + is generally kept in a file called COPYING or LICENSE. If you do not + have a copy of the license, write to the Free Software Foundation, + 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#define READLINE_LIBRARY + +#if defined (HAVE_CONFIG_H) +# include <config.h> +#endif + +#include <stdio.h> + +#if defined (HAVE_STDLIB_H) +# include <stdlib.h> +#else +# include "ansi_stdlib.h" +#endif /* HAVE_STDLIB_H */ + +#if defined (HAVE_UNISTD_H) +# ifndef _MINIX +# include <sys/types.h> +# endif +# include <unistd.h> +#endif + +#if defined (HAVE_STRING_H) +# include <string.h> +#else +# include <strings.h> +#endif /* !HAVE_STRING_H */ + +#include "history.h" +#include "histlib.h" + +#define HISTORY_WORD_DELIMITERS " \t\n;&()|<>" +#define HISTORY_QUOTE_CHARACTERS "\"'`" + +static char error_pointer; + +static char *subst_lhs; +static char *subst_rhs; +static int subst_lhs_len; +static int subst_rhs_len; + +static char *get_history_word_specifier (); +static char *history_find_word (); + +extern int history_offset; + +extern char *single_quote (); +static char *quote_breaks (); + +extern char *xmalloc (), *xrealloc (); + +/* Variables exported by this file. */ +/* The character that represents the start of a history expansion + request. This is usually `!'. */ +char history_expansion_char = '!'; + +/* The character that invokes word substitution if found at the start of + a line. This is usually `^'. */ +char history_subst_char = '^'; + +/* During tokenization, if this character is seen as the first character + of a word, then it, and all subsequent characters upto a newline are + ignored. For a Bourne shell, this should be '#'. Bash special cases + the interactive comment character to not be a comment delimiter. */ +char history_comment_char = '\0'; + +/* The list of characters which inhibit the expansion of text if found + immediately following history_expansion_char. */ +char *history_no_expand_chars = " \t\n\r="; + +/* If set to a non-zero value, single quotes inhibit history expansion. + The default is 0. */ +int history_quotes_inhibit_expansion = 0; + +/* If set, this points to a function that is called to verify that a + particular history expansion should be performed. */ +Function *history_inhibit_expansion_function; + +/* **************************************************************** */ +/* */ +/* History Expansion */ +/* */ +/* **************************************************************** */ + +/* Hairy history expansion on text, not tokens. This is of general + use, and thus belongs in this library. */ + +/* The last string searched for by a !?string? search. */ +static char *search_string; + +/* The last string matched by a !?string? search. */ +static char *search_match; + +/* Return the event specified at TEXT + OFFSET modifying OFFSET to + point to after the event specifier. Just a pointer to the history + line is returned; NULL is returned in the event of a bad specifier. + You pass STRING with *INDEX equal to the history_expansion_char that + begins this specification. + DELIMITING_QUOTE is a character that is allowed to end the string + specification for what to search for in addition to the normal + characters `:', ` ', `\t', `\n', and sometimes `?'. + So you might call this function like: + line = get_history_event ("!echo:p", &index, 0); */ +char * +get_history_event (string, caller_index, delimiting_quote) + char *string; + int *caller_index; + int delimiting_quote; +{ + register int i; + register char c; + HIST_ENTRY *entry; + int which, sign, local_index, substring_okay; + Function *search_func; + char *temp; + + /* The event can be specified in a number of ways. + + !! the previous command + !n command line N + !-n current command-line minus N + !str the most recent command starting with STR + !?str[?] + the most recent command containing STR + + All values N are determined via HISTORY_BASE. */ + + i = *caller_index; + + if (string[i] != history_expansion_char) + return ((char *)NULL); + + /* Move on to the specification. */ + i++; + + sign = 1; + substring_okay = 0; + +#define RETURN_ENTRY(e, w) \ + return ((e = history_get (w)) ? e->line : (char *)NULL) + + /* Handle !! case. */ + if (string[i] == history_expansion_char) + { + i++; + which = history_base + (history_length - 1); + *caller_index = i; + RETURN_ENTRY (entry, which); + } + + /* Hack case of numeric line specification. */ + if (string[i] == '-') + { + sign = -1; + i++; + } + + if (_rl_digit_p (string[i])) + { + /* Get the extent of the digits and compute the value. */ + for (which = 0; _rl_digit_p (string[i]); i++) + which = (which * 10) + _rl_digit_value (string[i]); + + *caller_index = i; + + if (sign < 0) + which = (history_length + history_base) - which; + + RETURN_ENTRY (entry, which); + } + + /* This must be something to search for. If the spec begins with + a '?', then the string may be anywhere on the line. Otherwise, + the string must be found at the start of a line. */ + if (string[i] == '?') + { + substring_okay++; + i++; + } + + /* Only a closing `?' or a newline delimit a substring search string. */ + for (local_index = i; c = string[i]; i++) + if ((!substring_okay && (whitespace (c) || c == ':' || + (history_search_delimiter_chars && member (c, history_search_delimiter_chars)) || + string[i] == delimiting_quote)) || + string[i] == '\n' || + (substring_okay && string[i] == '?')) + break; + + which = i - local_index; + temp = xmalloc (1 + which); + if (which) + strncpy (temp, string + local_index, which); + temp[which] = '\0'; + + if (substring_okay && string[i] == '?') + i++; + + *caller_index = i; + +#define FAIL_SEARCH() \ + do { \ + history_offset = history_length; free (temp) ; return (char *)NULL; \ + } while (0) + + /* If there is no search string, try to use the previous search string, + if one exists. If not, fail immediately. */ + if (*temp == '\0' && substring_okay) + { + if (search_string) + { + free (temp); + temp = savestring (search_string); + } + else + FAIL_SEARCH (); + } + + search_func = substring_okay ? history_search : history_search_prefix; + while (1) + { + local_index = (*search_func) (temp, -1); + + if (local_index < 0) + FAIL_SEARCH (); + + if (local_index == 0 || substring_okay) + { + entry = current_history (); + history_offset = history_length; + + /* If this was a substring search, then remember the + string that we matched for word substitution. */ + if (substring_okay) + { + FREE (search_string); + search_string = temp; + + FREE (search_match); + search_match = history_find_word (entry->line, local_index); + } + else + free (temp); + + return (entry->line); + } + + if (history_offset) + history_offset--; + else + FAIL_SEARCH (); + } +#undef FAIL_SEARCH +#undef RETURN_ENTRY +} + +/* Function for extracting single-quoted strings. Used for inhibiting + history expansion within single quotes. */ + +/* Extract the contents of STRING as if it is enclosed in single quotes. + SINDEX, when passed in, is the offset of the character immediately + following the opening single quote; on exit, SINDEX is left pointing + to the closing single quote. */ +static void +hist_string_extract_single_quoted (string, sindex) + char *string; + int *sindex; +{ + register int i; + + for (i = *sindex; string[i] && string[i] != '\''; i++) + ; + + *sindex = i; +} + +static char * +quote_breaks (s) + char *s; +{ + register char *p, *r; + char *ret; + int len = 3; + + for (p = s; p && *p; p++, len++) + { + if (*p == '\'') + len += 3; + else if (whitespace (*p) || *p == '\n') + len += 2; + } + + r = ret = xmalloc (len); + *r++ = '\''; + for (p = s; p && *p; ) + { + if (*p == '\'') + { + *r++ = '\''; + *r++ = '\\'; + *r++ = '\''; + *r++ = '\''; + p++; + } + else if (whitespace (*p) || *p == '\n') + { + *r++ = '\''; + *r++ = *p++; + *r++ = '\''; + } + else + *r++ = *p++; + } + *r++ = '\''; + *r = '\0'; + return ret; +} + +static char * +hist_error(s, start, current, errtype) + char *s; + int start, current, errtype; +{ + char *temp, *emsg; + int ll, elen; + + ll = current - start; + + switch (errtype) + { + case EVENT_NOT_FOUND: + emsg = "event not found"; + elen = 15; + break; + case BAD_WORD_SPEC: + emsg = "bad word specifier"; + elen = 18; + break; + case SUBST_FAILED: + emsg = "substitution failed"; + elen = 19; + break; + case BAD_MODIFIER: + emsg = "unrecognized history modifier"; + elen = 29; + break; + default: + emsg = "unknown expansion error"; + elen = 23; + break; + } + + temp = xmalloc (ll + elen + 3); + strncpy (temp, s + start, ll); + temp[ll] = ':'; + temp[ll + 1] = ' '; + strcpy (temp + ll + 2, emsg); + return (temp); +} + +/* Get a history substitution string from STR starting at *IPTR + and return it. The length is returned in LENPTR. + + A backslash can quote the delimiter. If the string is the + empty string, the previous pattern is used. If there is + no previous pattern for the lhs, the last history search + string is used. + + If IS_RHS is 1, we ignore empty strings and set the pattern + to "" anyway. subst_lhs is not changed if the lhs is empty; + subst_rhs is allowed to be set to the empty string. */ + +static char * +get_subst_pattern (str, iptr, delimiter, is_rhs, lenptr) + char *str; + int *iptr, delimiter, is_rhs, *lenptr; +{ + register int si, i, j, k; + char *s = (char *) NULL; + + i = *iptr; + + for (si = i; str[si] && str[si] != delimiter; si++) + if (str[si] == '\\' && str[si + 1] == delimiter) + si++; + + if (si > i || is_rhs) + { + s = xmalloc (si - i + 1); + for (j = 0, k = i; k < si; j++, k++) + { + /* Remove a backslash quoting the search string delimiter. */ + if (str[k] == '\\' && str[k + 1] == delimiter) + k++; + s[j] = str[k]; + } + s[j] = '\0'; + if (lenptr) + *lenptr = j; + } + + i = si; + if (str[i]) + i++; + *iptr = i; + + return s; +} + +static void +postproc_subst_rhs () +{ + char *new; + int i, j, new_size; + + new = xmalloc (new_size = subst_rhs_len + subst_lhs_len); + for (i = j = 0; i < subst_rhs_len; i++) + { + if (subst_rhs[i] == '&') + { + if (j + subst_lhs_len >= new_size) + new = xrealloc (new, (new_size = new_size * 2 + subst_lhs_len)); + strcpy (new + j, subst_lhs); + j += subst_lhs_len; + } + else + { + /* a single backslash protects the `&' from lhs interpolation */ + if (subst_rhs[i] == '\\' && subst_rhs[i + 1] == '&') + i++; + if (j >= new_size) + new = xrealloc (new, new_size *= 2); + new[j++] = subst_rhs[i]; + } + } + new[j] = '\0'; + free (subst_rhs); + subst_rhs = new; + subst_rhs_len = j; +} + +/* Expand the bulk of a history specifier starting at STRING[START]. + Returns 0 if everything is OK, -1 if an error occurred, and 1 + if the `p' modifier was supplied and the caller should just print + the returned string. Returns the new index into string in + *END_INDEX_PTR, and the expanded specifier in *RET_STRING. */ +static int +history_expand_internal (string, start, end_index_ptr, ret_string, current_line) + char *string; + int start, *end_index_ptr; + char **ret_string; + char *current_line; /* for !# */ +{ + int i, n, starting_index; + int substitute_globally, want_quotes, print_only; + char *event, *temp, *result, *tstr, *t, c, *word_spec; + int result_len; + + result = xmalloc (result_len = 128); + + i = start; + + /* If it is followed by something that starts a word specifier, + then !! is implied as the event specifier. */ + + if (member (string[i + 1], ":$*%^")) + { + char fake_s[3]; + int fake_i = 0; + i++; + fake_s[0] = fake_s[1] = history_expansion_char; + fake_s[2] = '\0'; + event = get_history_event (fake_s, &fake_i, 0); + } + else if (string[i + 1] == '#') + { + i += 2; + event = current_line; + } + else + { + int quoted_search_delimiter = 0; + + /* If the character before this `!' is a double or single + quote, then this expansion takes place inside of the + quoted string. If we have to search for some text ("!foo"), + allow the delimiter to end the search string. */ + if (i && (string[i - 1] == '\'' || string[i - 1] == '"')) + quoted_search_delimiter = string[i - 1]; + event = get_history_event (string, &i, quoted_search_delimiter); + } + + if (event == 0) + { + *ret_string = hist_error (string, start, i, EVENT_NOT_FOUND); + free (result); + return (-1); + } + + /* If a word specifier is found, then do what that requires. */ + starting_index = i; + word_spec = get_history_word_specifier (string, event, &i); + + /* There is no such thing as a `malformed word specifier'. However, + it is possible for a specifier that has no match. In that case, + we complain. */ + if (word_spec == (char *)&error_pointer) + { + *ret_string = hist_error (string, starting_index, i, BAD_WORD_SPEC); + free (result); + return (-1); + } + + /* If no word specifier, than the thing of interest was the event. */ + temp = word_spec ? savestring (word_spec) : savestring (event); + FREE (word_spec); + + /* Perhaps there are other modifiers involved. Do what they say. */ + want_quotes = substitute_globally = print_only = 0; + starting_index = i; + + while (string[i] == ':') + { + c = string[i + 1]; + + if (c == 'g') + { + substitute_globally = 1; + i++; + c = string[i + 1]; + } + + switch (c) + { + default: + *ret_string = hist_error (string, i+1, i+2, BAD_MODIFIER); + free (result); + free (temp); + return -1; + + case 'q': + want_quotes = 'q'; + break; + + case 'x': + want_quotes = 'x'; + break; + + /* :p means make this the last executed line. So we + return an error state after adding this line to the + history. */ + case 'p': + print_only++; + break; + + /* :t discards all but the last part of the pathname. */ + case 't': + tstr = strrchr (temp, '/'); + if (tstr) + { + tstr++; + t = savestring (tstr); + free (temp); + temp = t; + } + break; + + /* :h discards the last part of a pathname. */ + case 'h': + tstr = strrchr (temp, '/'); + if (tstr) + *tstr = '\0'; + break; + + /* :r discards the suffix. */ + case 'r': + tstr = strrchr (temp, '.'); + if (tstr) + *tstr = '\0'; + break; + + /* :e discards everything but the suffix. */ + case 'e': + tstr = strrchr (temp, '.'); + if (tstr) + { + t = savestring (tstr); + free (temp); + temp = t; + } + break; + + /* :s/this/that substitutes `that' for the first + occurrence of `this'. :gs/this/that substitutes `that' + for each occurrence of `this'. :& repeats the last + substitution. :g& repeats the last substitution + globally. */ + + case '&': + case 's': + { + char *new_event, *t; + int delimiter, failed, si, l_temp; + + if (c == 's') + { + if (i + 2 < (int)strlen (string)) + delimiter = string[i + 2]; + else + break; /* no search delimiter */ + + i += 3; + + t = get_subst_pattern (string, &i, delimiter, 0, &subst_lhs_len); + /* An empty substitution lhs with no previous substitution + uses the last search string as the lhs. */ + if (t) + { + FREE (subst_lhs); + subst_lhs = t; + } + else if (!subst_lhs) + { + if (search_string && *search_string) + { + subst_lhs = savestring (search_string); + subst_lhs_len = strlen (subst_lhs); + } + else + { + subst_lhs = (char *) NULL; + subst_lhs_len = 0; + } + } + + /* If there is no lhs, the substitution can't succeed. */ + if (subst_lhs_len == 0) + { + *ret_string = hist_error (string, starting_index, i, SUBST_FAILED); + free (result); + free (temp); + return -1; + } + + FREE (subst_rhs); + subst_rhs = get_subst_pattern (string, &i, delimiter, 1, &subst_rhs_len); + + /* If `&' appears in the rhs, it's supposed to be replaced + with the lhs. */ + if (member ('&', subst_rhs)) + postproc_subst_rhs (); + } + else + i += 2; + + l_temp = strlen (temp); + /* Ignore impossible cases. */ + if (subst_lhs_len > l_temp) + { + *ret_string = hist_error (string, starting_index, i, SUBST_FAILED); + free (result); + free (temp); + return (-1); + } + + /* Find the first occurrence of THIS in TEMP. */ + si = 0; + for (failed = 1; (si + subst_lhs_len) <= l_temp; si++) + if (STREQN (temp+si, subst_lhs, subst_lhs_len)) + { + int len = subst_rhs_len - subst_lhs_len + l_temp; + new_event = xmalloc (1 + len); + strncpy (new_event, temp, si); + strncpy (new_event + si, subst_rhs, subst_rhs_len); + strncpy (new_event + si + subst_rhs_len, + temp + si + subst_lhs_len, + l_temp - (si + subst_lhs_len)); + new_event[len] = '\0'; + free (temp); + temp = new_event; + + failed = 0; + + if (substitute_globally) + { + si += subst_rhs_len; + l_temp = strlen (temp); + substitute_globally++; + continue; + } + else + break; + } + + if (substitute_globally > 1) + { + substitute_globally = 0; + continue; /* don't want to increment i */ + } + + if (failed == 0) + continue; /* don't want to increment i */ + + *ret_string = hist_error (string, starting_index, i, SUBST_FAILED); + free (result); + free (temp); + return (-1); + } + } + i += 2; + } + /* Done with modfiers. */ + /* Believe it or not, we have to back the pointer up by one. */ + --i; + + if (want_quotes) + { + char *x; + + if (want_quotes == 'q') + x = single_quote (temp); + else if (want_quotes == 'x') + x = quote_breaks (temp); + else + x = savestring (temp); + + free (temp); + temp = x; + } + + n = strlen (temp); + if (n >= result_len) + result = xrealloc (result, n + 2); + strcpy (result, temp); + free (temp); + + *end_index_ptr = i; + *ret_string = result; + return (print_only); +} + +/* Expand the string STRING, placing the result into OUTPUT, a pointer + to a string. Returns: + + -1) If there was an error in expansion. + 0) If no expansions took place (or, if the only change in + the text was the de-slashifying of the history expansion + character) + 1) If expansions did take place + 2) If the `p' modifier was given and the caller should print the result + + If an error ocurred in expansion, then OUTPUT contains a descriptive + error message. */ + +#define ADD_STRING(s) \ + do \ + { \ + int sl = strlen (s); \ + j += sl; \ + if (j >= result_len) \ + { \ + while (j >= result_len) \ + result_len += 128; \ + result = xrealloc (result, result_len); \ + } \ + strcpy (result + j - sl, s); \ + } \ + while (0) + +#define ADD_CHAR(c) \ + do \ + { \ + if (j >= result_len - 1) \ + result = xrealloc (result, result_len += 64); \ + result[j++] = c; \ + result[j] = '\0'; \ + } \ + while (0) + +int +history_expand (hstring, output) + char *hstring; + char **output; +{ + register int j; + int i, r, l, passc, cc, modified, eindex, only_printing; + char *string; + + /* The output string, and its length. */ + int result_len; + char *result; + + /* Used when adding the string. */ + char *temp; + + /* Setting the history expansion character to 0 inhibits all + history expansion. */ + if (history_expansion_char == 0) + { + *output = savestring (hstring); + return (0); + } + + /* Prepare the buffer for printing error messages. */ + result = xmalloc (result_len = 256); + result[0] = '\0'; + + only_printing = modified = 0; + l = strlen (hstring); + + /* Grovel the string. Only backslash and single quotes can quote the + history escape character. We also handle arg specifiers. */ + + /* Before we grovel forever, see if the history_expansion_char appears + anywhere within the text. */ + + /* The quick substitution character is a history expansion all right. That + is to say, "^this^that^" is equivalent to "!!:s^this^that^", and in fact, + that is the substitution that we do. */ + if (hstring[0] == history_subst_char) + { + string = xmalloc (l + 5); + + string[0] = string[1] = history_expansion_char; + string[2] = ':'; + string[3] = 's'; + strcpy (string + 4, hstring); + l += 4; + } + else + { + string = hstring; + /* If not quick substitution, still maybe have to do expansion. */ + + /* `!' followed by one of the characters in history_no_expand_chars + is NOT an expansion. */ + for (i = 0; string[i]; i++) + { + cc = string[i + 1]; + /* The history_comment_char, if set, appearing that the beginning + of a word signifies that the rest of the line should not have + history expansion performed on it. + Skip the rest of the line and break out of the loop. */ + if (history_comment_char && string[i] == history_comment_char && + (i == 0 || member (string[i - 1], HISTORY_WORD_DELIMITERS))) + { + while (string[i]) + i++; + break; + } + else if (string[i] == history_expansion_char) + { + if (!cc || member (cc, history_no_expand_chars)) + continue; + /* If the calling application has set + history_inhibit_expansion_function to a function that checks + for special cases that should not be history expanded, + call the function and skip the expansion if it returns a + non-zero value. */ + else if (history_inhibit_expansion_function && + (*history_inhibit_expansion_function) (string, i)) + continue; + else + break; + } + /* XXX - at some point, might want to extend this to handle + double quotes as well. */ + else if (history_quotes_inhibit_expansion && string[i] == '\'') + { + /* If this is bash, single quotes inhibit history expansion. */ + i++; + hist_string_extract_single_quoted (string, &i); + } + else if (history_quotes_inhibit_expansion && string[i] == '\\') + { + /* If this is bash, allow backslashes to quote single + quotes and the history expansion character. */ + if (cc == '\'' || cc == history_expansion_char) + i++; + } + } + + if (string[i] != history_expansion_char) + { + free (result); + *output = savestring (string); + return (0); + } + } + + /* Extract and perform the substitution. */ + for (passc = i = j = 0; i < l; i++) + { + int tchar = string[i]; + + if (passc) + { + passc = 0; + ADD_CHAR (tchar); + continue; + } + + if (tchar == history_expansion_char) + tchar = -3; + else if (tchar == history_comment_char) + tchar = -2; + + switch (tchar) + { + default: + ADD_CHAR (string[i]); + break; + + case '\\': + passc++; + ADD_CHAR (tchar); + break; + + case '\'': + { + /* If history_quotes_inhibit_expansion is set, single quotes + inhibit history expansion. */ + if (history_quotes_inhibit_expansion) + { + int quote, slen; + + quote = i++; + hist_string_extract_single_quoted (string, &i); + + slen = i - quote + 2; + temp = xmalloc (slen); + strncpy (temp, string + quote, slen); + temp[slen - 1] = '\0'; + ADD_STRING (temp); + free (temp); + } + else + ADD_CHAR (string[i]); + break; + } + + case -2: /* history_comment_char */ + if (i == 0 || member (string[i - 1], HISTORY_WORD_DELIMITERS)) + { + temp = xmalloc (l - i + 1); + strcpy (temp, string + i); + ADD_STRING (temp); + free (temp); + i = l; + } + else + ADD_CHAR (string[i]); + break; + + case -3: /* history_expansion_char */ + cc = string[i + 1]; + + /* If the history_expansion_char is followed by one of the + characters in history_no_expand_chars, then it is not a + candidate for expansion of any kind. */ + if (member (cc, history_no_expand_chars)) + { + ADD_CHAR (string[i]); + break; + } + +#if defined (NO_BANG_HASH_MODIFIERS) + /* There is something that is listed as a `word specifier' in csh + documentation which means `the expanded text to this point'. + That is not a word specifier, it is an event specifier. If we + don't want to allow modifiers with `!#', just stick the current + output line in again. */ + if (cc == '#') + { + if (result) + { + temp = xmalloc (1 + strlen (result)); + strcpy (temp, result); + ADD_STRING (temp); + free (temp); + } + i++; + break; + } +#endif + + r = history_expand_internal (string, i, &eindex, &temp, result); + if (r < 0) + { + *output = temp; + free (result); + if (string != hstring) + free (string); + return -1; + } + else + { + if (temp) + { + modified++; + if (*temp) + ADD_STRING (temp); + free (temp); + } + only_printing = r == 1; + i = eindex; + } + break; + } + } + + *output = result; + if (string != hstring) + free (string); + + if (only_printing) + { + add_history (result); + return (2); + } + + return (modified != 0); +} + +/* Return a consed string which is the word specified in SPEC, and found + in FROM. NULL is returned if there is no spec. The address of + ERROR_POINTER is returned if the word specified cannot be found. + CALLER_INDEX is the offset in SPEC to start looking; it is updated + to point to just after the last character parsed. */ +static char * +get_history_word_specifier (spec, from, caller_index) + char *spec, *from; + int *caller_index; +{ + register int i = *caller_index; + int first, last; + int expecting_word_spec = 0; + char *result; + + /* The range of words to return doesn't exist yet. */ + first = last = 0; + result = (char *)NULL; + + /* If we found a colon, then this *must* be a word specification. If + it isn't, then it is an error. */ + if (spec[i] == ':') + { + i++; + expecting_word_spec++; + } + + /* Handle special cases first. */ + + /* `%' is the word last searched for. */ + if (spec[i] == '%') + { + *caller_index = i + 1; + return (search_match ? savestring (search_match) : savestring ("")); + } + + /* `*' matches all of the arguments, but not the command. */ + if (spec[i] == '*') + { + *caller_index = i + 1; + result = history_arg_extract (1, '$', from); + return (result ? result : savestring ("")); + } + + /* `$' is last arg. */ + if (spec[i] == '$') + { + *caller_index = i + 1; + return (history_arg_extract ('$', '$', from)); + } + + /* Try to get FIRST and LAST figured out. */ + + if (spec[i] == '-') + first = 0; + else if (spec[i] == '^') + first = 1; + else if (_rl_digit_p (spec[i]) && expecting_word_spec) + { + for (first = 0; _rl_digit_p (spec[i]); i++) + first = (first * 10) + _rl_digit_value (spec[i]); + } + else + return ((char *)NULL); /* no valid `first' for word specifier */ + + if (spec[i] == '^' || spec[i] == '*') + { + last = (spec[i] == '^') ? 1 : '$'; /* x* abbreviates x-$ */ + i++; + } + else if (spec[i] != '-') + last = first; + else + { + i++; + + if (_rl_digit_p (spec[i])) + { + for (last = 0; _rl_digit_p (spec[i]); i++) + last = (last * 10) + _rl_digit_value (spec[i]); + } + else if (spec[i] == '$') + { + i++; + last = '$'; + } + else if (!spec[i] || spec[i] == ':') /* could be modifier separator */ + last = -1; /* x- abbreviates x-$ omitting word `$' */ + } + + *caller_index = i; + + if (last >= first || last == '$' || last < 0) + result = history_arg_extract (first, last, from); + + return (result ? result : (char *)&error_pointer); +} + +/* Extract the args specified, starting at FIRST, and ending at LAST. + The args are taken from STRING. If either FIRST or LAST is < 0, + then make that arg count from the right (subtract from the number of + tokens, so that FIRST = -1 means the next to last token on the line). + If LAST is `$' the last arg from STRING is used. */ +char * +history_arg_extract (first, last, string) + int first, last; + char *string; +{ + register int i, len; + char *result; + int size, offset; + char **list; + + /* XXX - think about making history_tokenize return a struct array, + each struct in array being a string and a length to avoid the + calls to strlen below. */ + if ((list = history_tokenize (string)) == NULL) + return ((char *)NULL); + + for (len = 0; list[len]; len++) + ; + + if (last < 0) + last = len + last - 1; + + if (first < 0) + first = len + first - 1; + + if (last == '$') + last = len - 1; + + if (first == '$') + first = len - 1; + + last++; + + if (first >= len || last > len || first < 0 || last < 0 || first > last) + result = ((char *)NULL); + else + { + for (size = 0, i = first; i < last; i++) + size += strlen (list[i]) + 1; + result = xmalloc (size + 1); + result[0] = '\0'; + + for (i = first, offset = 0; i < last; i++) + { + strcpy (result + offset, list[i]); + offset += strlen (list[i]); + if (i + 1 < last) + { + result[offset++] = ' '; + result[offset] = 0; + } + } + } + + for (i = 0; i < len; i++) + free (list[i]); + free (list); + + return (result); +} + +#define slashify_in_quotes "\\`\"$" + +/* Parse STRING into tokens and return an array of strings. If WIND is + not -1 and INDP is not null, we also want the word surrounding index + WIND. The position in the returned array of strings is returned in + *INDP. */ +static char ** +history_tokenize_internal (string, wind, indp) + char *string; + int wind, *indp; +{ + char **result; + register int i, start, result_index, size; + int len, delimiter; + + /* Get a token, and stuff it into RESULT. The tokens are split + exactly where the shell would split them. */ + for (i = result_index = size = 0, result = (char **)NULL; string[i]; ) + { + delimiter = 0; + + /* Skip leading whitespace. */ + for (; string[i] && whitespace (string[i]); i++) + ; + if (string[i] == 0 || string[i] == history_comment_char) + return (result); + + start = i; + + if (member (string[i], "()\n")) + { + i++; + goto got_token; + } + + if (member (string[i], "<>;&|$")) + { + int peek = string[i + 1]; + + if (peek == string[i] && peek != '$') + { + if (peek == '<' && string[i + 2] == '-') + i++; + i += 2; + goto got_token; + } + else + { + if ((peek == '&' && (string[i] == '>' || string[i] == '<')) || + ((peek == '>') && (string[i] == '&')) || + ((peek == '(') && (string[i] == '$'))) + { + i += 2; + goto got_token; + } + } + if (string[i] != '$') + { + i++; + goto got_token; + } + } + + /* Get word from string + i; */ + + if (member (string[i], HISTORY_QUOTE_CHARACTERS)) + delimiter = string[i++]; + + for (; string[i]; i++) + { + if (string[i] == '\\' && string[i + 1] == '\n') + { + i++; + continue; + } + + if (string[i] == '\\' && delimiter != '\'' && + (delimiter != '"' || member (string[i], slashify_in_quotes))) + { + i++; + continue; + } + + if (delimiter && string[i] == delimiter) + { + delimiter = 0; + continue; + } + + if (!delimiter && (member (string[i], HISTORY_WORD_DELIMITERS))) + break; + + if (!delimiter && member (string[i], HISTORY_QUOTE_CHARACTERS)) + delimiter = string[i]; + } + + got_token: + + /* If we are looking for the word in which the character at a + particular index falls, remember it. */ + if (indp && wind != -1 && wind >= start && wind < i) + *indp = result_index; + + len = i - start; + if (result_index + 2 >= size) + result = (char **)xrealloc (result, ((size += 10) * sizeof (char *))); + result[result_index] = xmalloc (1 + len); + strncpy (result[result_index], string + start, len); + result[result_index][len] = '\0'; + result[++result_index] = (char *)NULL; + } + + return (result); +} + +/* Return an array of tokens, much as the shell might. The tokens are + parsed out of STRING. */ +char ** +history_tokenize (string) + char *string; +{ + return (history_tokenize_internal (string, -1, (int *)NULL)); +} + +/* Find and return the word which contains the character at index IND + in the history line LINE. Used to save the word matched by the + last history !?string? search. */ +static char * +history_find_word (line, ind) + char *line; + int ind; +{ + char **words, *s; + int i, wind; + + words = history_tokenize_internal (line, ind, &wind); + if (wind == -1) + return ((char *)NULL); + s = words[wind]; + for (i = 0; i < wind; i++) + free (words[i]); + for (i = wind + 1; words[i]; i++) + free (words[i]); + free (words); + return s; +} |