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uemacs/isearch.c

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/* ISEARCH.C
*
* The functions in this file implement commands that perform incremental
* searches in the forward and backward directions. This "ISearch" command
* is intended to emulate the same command from the original EMACS
* implementation (ITS). Contains references to routines internal to
* SEARCH.C.
*
* REVISION HISTORY:
*
* D. R. Banks 9-May-86
* - added ITS EMACSlike ISearch
*
* John M. Gamble 5-Oct-86
* - Made iterative search use search.c's scanner() routine.
* This allowed the elimination of bakscan().
* - Put isearch constants into estruct.h
* - Eliminated the passing of 'status' to scanmore() and
* checknext(), since there were no circumstances where
* it ever equalled FALSE.
*
* modified by Petri Kutvonen
*/
#include <stdio.h>
#include "estruct.h"
#include "edef.h"
#if ISRCH
extern int scanner(); /* Handy search routine */
extern int eq(); /* Compare chars, match case */
/* A couple of "own" variables for re-eat */
int (*saved_get_char)(); /* Get character routine */
int eaten_char = -1; /* Re-eaten char */
/* A couple more "own" variables for the command string */
int cmd_buff[CMDBUFLEN]; /* Save the command args here */
int cmd_offset; /* Current offset into command buff */
int cmd_reexecute = -1; /* > 0 if re-executing command */
/*
* Subroutine to do incremental reverse search. It actually uses the
* same code as the normal incremental search, as both can go both ways.
*/
int risearch(f, n)
{
LINE *curline; /* Current line on entry */
int curoff; /* Current offset on entry */
/* remember the initial . on entry: */
curline = curwp->w_dotp; /* Save the current line pointer */
curoff = curwp->w_doto; /* Save the current offset */
/* Make sure the search doesn't match where we already are: */
backchar(TRUE, 1); /* Back up a character */
if (!(isearch(f, -n))) /* Call ISearch backwards */
{ /* If error in search: */
curwp->w_dotp = curline; /* Reset the line pointer */
curwp->w_doto = curoff; /* and the offset to original value */
curwp->w_flag |= WFMOVE; /* Say we've moved */
update(FALSE); /* And force an update */
mlwrite ("(search failed)"); /* Say we died */
#if PKCODE
matchlen = strlen(pat);
#endif
} else mlerase (); /* If happy, just erase the cmd line */
#if PKCODE
matchlen = strlen(pat);
#endif
}
/* Again, but for the forward direction */
int fisearch(f, n)
{
LINE *curline; /* Current line on entry */
int curoff; /* Current offset on entry */
/* remember the initial . on entry: */
curline = curwp->w_dotp; /* Save the current line pointer */
curoff = curwp->w_doto; /* Save the current offset */
/* do the search */
if (!(isearch(f, n))) /* Call ISearch forwards */
{ /* If error in search: */
curwp->w_dotp = curline; /* Reset the line pointer */
curwp->w_doto = curoff; /* and the offset to original value */
curwp->w_flag |= WFMOVE; /* Say we've moved */
update(FALSE); /* And force an update */
mlwrite ("(search failed)"); /* Say we died */
#if PKCODE
matchlen = strlen(pat);
#endif
} else mlerase (); /* If happy, just erase the cmd line */
#if PKCODE
matchlen = strlen(pat);
#endif
}
/*
* Subroutine to do an incremental search. In general, this works similarly
* to the older micro-emacs search function, except that the search happens
* as each character is typed, with the screen and cursor updated with each
* new search character.
*
* While searching forward, each successive character will leave the cursor
* at the end of the entire matched string. Typing a Control-S or Control-X
* will cause the next occurrence of the string to be searched for (where the
* next occurrence does NOT overlap the current occurrence). A Control-R will
* change to a backwards search, META will terminate the search and Control-G
* will abort the search. Rubout will back up to the previous match of the
* string, or if the starting point is reached first, it will delete the
* last character from the search string.
*
* While searching backward, each successive character will leave the cursor
* at the beginning of the matched string. Typing a Control-R will search
* backward for the next occurrence of the string. Control-S or Control-X
* will revert the search to the forward direction. In general, the reverse
* incremental search is just like the forward incremental search inverted.
*
* In all cases, if the search fails, the user will be feeped, and the search
* will stall until the pattern string is edited back into something that
* exists (or until the search is aborted).
*/
isearch(f, n)
{
int status; /* Search status */
int col; /* prompt column */
register int cpos; /* character number in search string */
register int c; /* current input character */
register int expc; /* function expanded input char */
char pat_save[NPAT]; /* Saved copy of the old pattern str */
LINE *curline; /* Current line on entry */
int curoff; /* Current offset on entry */
int init_direction; /* The initial search direction */
/* Initialize starting conditions */
cmd_reexecute = -1; /* We're not re-executing (yet?) */
cmd_offset = 0; /* Start at the beginning of the buff */
cmd_buff[0] = '\0'; /* Init the command buffer */
strncpy (pat_save, pat, NPAT); /* Save the old pattern string */
curline = curwp->w_dotp; /* Save the current line pointer */
curoff = curwp->w_doto; /* Save the current offset */
init_direction = n; /* Save the initial search direction */
/* This is a good place to start a re-execution: */
start_over:
/* ask the user for the text of a pattern */
col = promptpattern("ISearch: "); /* Prompt, remember the col */
cpos = 0; /* Start afresh */
status = TRUE; /* Assume everything's cool */
/*
Get the first character in the pattern. If we get an initial Control-S
or Control-R, re-use the old search string and find the first occurrence
*/
c = ectoc(expc = get_char()); /* Get the first character */
if ((c == IS_FORWARD) ||
(c == IS_REVERSE) ||
(c == IS_VMSFORW)) /* Reuse old search string? */
{
for (cpos = 0; pat[cpos] != 0; cpos++) /* Yup, find the length */
col = echochar(pat[cpos],col); /* and re-echo the string */
if (c == IS_REVERSE) { /* forward search? */
n = -1; /* No, search in reverse */
backchar (TRUE, 1); /* Be defensive about EOB */
} else
n = 1; /* Yes, search forward */
status = scanmore(pat, n); /* Do the search */
c = ectoc(expc = get_char()); /* Get another character */
}
/* Top of the per character loop */
for (;;) /* ISearch per character loop */
{
/* Check for special characters first: */
/* Most cases here change the search */
if (expc == metac) /* Want to quit searching? */
return (TRUE); /* Quit searching now */
switch (c) /* dispatch on the input char */
{
case IS_ABORT: /* If abort search request */
return(FALSE); /* Quit searching again */
case IS_REVERSE: /* If backward search */
case IS_FORWARD: /* If forward search */
case IS_VMSFORW: /* of either flavor */
if (c == IS_REVERSE) /* If reverse search */
n = -1; /* Set the reverse direction */
else /* Otherwise, */
n = 1; /* go forward */
status = scanmore(pat, n); /* Start the search again */
c = ectoc(expc = get_char()); /* Get the next char */
continue; /* Go continue with the search*/
case IS_NEWLINE: /* Carriage return */
c = '\n'; /* Make it a new line */
break; /* Make sure we use it */
case IS_QUOTE: /* Quote character */
case IS_VMSQUOTE: /* of either variety */
c = ectoc(expc = get_char()); /* Get the next char */
case IS_TAB: /* Generically allowed */
case '\n': /* controlled characters */
break; /* Make sure we use it */
case IS_BACKSP: /* If a backspace: */
case IS_RUBOUT: /* or if a Rubout: */
if (cmd_offset <= 1) /* Anything to delete? */
return (TRUE); /* No, just exit */
--cmd_offset; /* Back up over the Rubout */
cmd_buff[--cmd_offset] = '\0'; /* Yes, delete last char */
curwp->w_dotp = curline; /* Reset the line pointer */
curwp->w_doto = curoff; /* and the offset */
n = init_direction; /* Reset the search direction */
strncpy (pat, pat_save, NPAT); /* Restore the old search str */
cmd_reexecute = 0; /* Start the whole mess over */
goto start_over; /* Let it take care of itself */
/* Presumably a quasi-normal character comes here */
default: /* All other chars */
if (c < ' ') /* Is it printable? */
{ /* Nope. */
reeat (c); /* Re-eat the char */
return (TRUE); /* And return the last status */
}
} /* Switch */
/* I guess we got something to search for, so search for it */
pat[cpos++] = c; /* put the char in the buffer */
if (cpos >= NPAT) /* too many chars in string? */
{ /* Yup. Complain about it */
mlwrite("? Search string too long");
return(TRUE); /* Return an error */
}
pat[cpos] = 0; /* null terminate the buffer */
col = echochar(c,col); /* Echo the character */
if (!status) { /* If we lost last time */
TTputc(BELL); /* Feep again */
TTflush(); /* see that the feep feeps */
} else /* Otherwise, we must have won*/
if (!(status = checknext(c, pat, n))) /* See if match */
status = scanmore(pat, n); /* or find the next match */
c = ectoc(expc = get_char()); /* Get the next char */
} /* for {;;} */
}
/*
* Trivial routine to insure that the next character in the search string is
* still true to whatever we're pointing to in the buffer. This routine will
* not attempt to move the "point" if the match fails, although it will
* implicitly move the "point" if we're forward searching, and find a match,
* since that's the way forward isearch works.
*
* If the compare fails, we return FALSE and assume the caller will call
* scanmore or something.
*/
int checknext (chr, patrn, dir) /* Check next character in search string */
char chr; /* Next char to look for */
char *patrn; /* The entire search string (incl chr) */
int dir; /* Search direction */
{
register LINE *curline; /* current line during scan */
register int curoff; /* position within current line */
register int buffchar; /* character at current position */
int status; /* how well things go */
/* setup the local scan pointer to current "." */
curline = curwp->w_dotp; /* Get the current line structure */
curoff = curwp->w_doto; /* Get the offset within that line */
if (dir > 0) /* If searching forward */
{
if (curoff == llength(curline)) /* If at end of line */
{
curline = lforw(curline); /* Skip to the next line */
if (curline == curbp->b_linep)
return (FALSE); /* Abort if at end of buffer */
curoff = 0; /* Start at the beginning of the line */
buffchar = '\n'; /* And say the next char is NL */
} else
buffchar = lgetc(curline, curoff++); /* Get the next char */
if (status = eq(buffchar, chr)) /* Is it what we're looking for? */
{
curwp->w_dotp = curline; /* Yes, set the buffer's point */
curwp->w_doto = curoff; /* to the matched character */
curwp->w_flag |= WFMOVE; /* Say that we've moved */
}
return (status); /* And return the status */
} else /* Else, if reverse search: */
return (match_pat (patrn)); /* See if we're in the right place */
}
/*
* This hack will search for the next occurrence of <pat> in the buffer, either
* forward or backward. It is called with the status of the prior search
* attempt, so that it knows not to bother if it didn't work last time. If
* we can't find any more matches, "point" is left where it was before. If
* we do find a match, "point" will be at the end of the matched string for
* forward searches and at the beginning of the matched string for reverse
* searches.
*/
int scanmore(patrn, dir) /* search forward or back for a pattern */
char *patrn; /* string to scan for */
int dir; /* direction to search */
{
int sts; /* search status */
if (dir < 0) /* reverse search? */
{
rvstrcpy(tap, patrn); /* Put reversed string in tap */
sts = scanner(tap, REVERSE, PTBEG);
}
else
sts = scanner(patrn, FORWARD, PTEND); /* Nope. Go forward */
if (!sts)
{
TTputc(BELL); /* Feep if search fails */
TTflush(); /* see that the feep feeps */
}
return(sts); /* else, don't even try */
}
/*
* The following is a worker subroutine used by the reverse search. It
* compares the pattern string with the characters at "." for equality. If
* any characters mismatch, it will return FALSE.
*
* This isn't used for forward searches, because forward searches leave "."
* at the end of the search string (instead of in front), so all that needs to
* be done is match the last char input.
*/
int match_pat (patrn) /* See if the pattern string matches string at "." */
char *patrn; /* String to match to buffer */
{
register int i; /* Generic loop index/offset */
register int buffchar; /* character at current position */
register LINE *curline; /* current line during scan */
register int curoff; /* position within current line */
/* setup the local scan pointer to current "." */
curline = curwp->w_dotp; /* Get the current line structure */
curoff = curwp->w_doto; /* Get the offset within that line */
/* top of per character compare loop: */
for (i = 0; i < strlen(patrn); i++) /* Loop for all characters in patrn */
{
if (curoff == llength(curline)) /* If at end of line */
{
curline = lforw(curline); /* Skip to the next line */
curoff = 0; /* Start at the beginning of the line */
if (curline == curbp->b_linep)
return (FALSE); /* Abort if at end of buffer */
buffchar = '\n'; /* And say the next char is NL */
} else
buffchar = lgetc(curline, curoff++); /* Get the next char */
if (!eq(buffchar, patrn[i])) /* Is it what we're looking for? */
return (FALSE); /* Nope, just punt it then */
}
return (TRUE); /* Everything matched? Let's celebrate*/
}
/* Routine to prompt for I-Search string. */
int promptpattern(prompt)
char *prompt;
{
char tpat[NPAT+20];
strcpy(tpat, prompt); /* copy prompt to output string */
strcat(tpat, " ("); /* build new prompt string */
expandp(pat, &tpat[strlen(tpat)], NPAT/2); /* add old pattern */
strcat(tpat, ")<Meta>: ");
/* check to see if we are executing a command line */
if (!clexec) {
mlwrite(tpat);
}
return(strlen(tpat));
}
/* routine to echo i-search characters */
int echochar(c,col)
int c; /* character to be echoed */
int col; /* column to be echoed in */
{
movecursor(term.t_nrow,col); /* Position the cursor */
if ((c < ' ') || (c == 0x7F)) /* Control character? */
{
switch (c) /* Yes, dispatch special cases*/
{
case '\n': /* Newline */
TTputc('<');
TTputc('N');
TTputc('L');
TTputc('>');
col += 3;
break;
case '\t': /* Tab */
TTputc('<');
TTputc('T');
TTputc('A');
TTputc('B');
TTputc('>');
col += 4;
break;
case 0x7F: /* Rubout: */
TTputc('^'); /* Output a funny looking */
TTputc('?'); /* indication of Rubout */
col++; /* Count the extra char */
break;
default: /* Vanilla control char */
TTputc('^'); /* Yes, output prefix */
TTputc(c+0x40); /* Make it "^X" */
col++; /* Count this char */
}
} else
TTputc(c); /* Otherwise, output raw char */
TTflush(); /* Flush the output */
return(++col); /* return the new column no */
}
/*
* Routine to get the next character from the input stream. If we're reading
* from the real terminal, force a screen update before we get the char.
* Otherwise, we must be re-executing the command string, so just return the
* next character.
*/
int get_char ()
{
int c; /* A place to get a character */
/* See if we're re-executing: */
if (cmd_reexecute >= 0) /* Is there an offset? */
if ((c = cmd_buff[cmd_reexecute++]) != 0)
return (c); /* Yes, return any character */
/* We're not re-executing (or aren't any more). Try for a real char */
cmd_reexecute = -1; /* Say we're in real mode again */
update(FALSE); /* Pretty up the screen */
if (cmd_offset >= CMDBUFLEN-1) /* If we're getting too big ... */
{
mlwrite ("? command too long"); /* Complain loudly and bitterly */
return (metac); /* And force a quit */
}
c = get1key(); /* Get the next character */
cmd_buff[cmd_offset++] = c; /* Save the char for next time */
cmd_buff[cmd_offset] = '\0';/* And terminate the buffer */
return (c); /* Return the character */
}
/*
* Hacky routine to re-eat a character. This will save the character to be
* re-eaten by redirecting the input call to a routine here. Hack, etc.
*/
/* Come here on the next term.t_getchar call: */
int uneat()
{
int c;
term.t_getchar = saved_get_char; /* restore the routine address */
c = eaten_char; /* Get the re-eaten char */
eaten_char = -1; /* Clear the old char */
return(c); /* and return the last char */
}
int reeat(c)
int c;
{
if (eaten_char != -1) /* If we've already been here */
return/*(NULL)*/; /* Don't do it again */
eaten_char = c; /* Else, save the char for later */
saved_get_char = term.t_getchar; /* Save the char get routine */
term.t_getchar = uneat; /* Replace it with ours */
}
#else
isearch()
{
}
#endif
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