freebsd-dev/usr.bin/more/macro.c
1999-09-05 19:13:04 +00:00

293 lines
8.0 KiB
C

/*-
* Copyright (c) 1999 Timmy M. Vanderhoek
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
/*
* Expansion of macros.
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "less.h"
/*
* Used to construct tables of macros. Each macro string expands to command.
* A number N is associated with each execution of a macro. The command
* "set number <N>" will be done before the expansion. The end of the table is
* specified by mactabsize. A NULL entry for command denotes a macro that
* has been marked deleted for some reason. As of this writing, there is no
* code that actually deletes a macro...
*/
struct macro {
char *string; /* characters typed to activate macro */
char *command; /* command resulting after the macro is activated */
long defnumber; /* default value of the N number */
int flags; /* only holds STICKYNUMB for now... */
};
/* (struct macro) ->flags */
#define NOFLAGS 0
#define STICKYNUMB 1 /* Set defnumber to current number, if current number */
/*
* The macro table.
*/
struct macro *mactab = NULL;
int mactabsize = 0;
static enum runmacro runmacro_();
static struct macro *matchmac();
/*
* XXX Everything's really just a macro until resolved as a quantum wave
* probability distribution.
*/
/*
* Attempts to run the appropriate macro. Returns 0, or OK, if the macro
* was succesfully run. Returns BADMACRO and sets erreur if something is
* horribly wrong with the macro. Returns NOMACRO if the macro has no valid
* expansion. BADMACRO and NOMACRO are almost the same. Returns BADCOMMAND
* and leaves erreur set (hopefully it was set when runmacro() tried to execute
* the command associated with the macro) if the command associated with
* the macro was unsuccessful. Returns TOOMACRO if the macro appears to be
* incomplete (ie. the user has not finished typing it in yet). The erreur
* is not set in this case.
*
* XXX There's no good reason not to just disallow badmacros from within
* setmacro() ... It's not clear what the author was thinking at the time.
*/
enum runmacro
runmacro(macro, number, anyN)
const char *macro; /* the macro string to try and expand */
long number; /* the number N associated with this execution */
int anyN; /* FALSE is we should use the default N associated with
* the macro. TRUE if we should use the number argument. */
{
struct macro *cur, *matched;
int match, yetmatch;
int s;
if (!mactab) {
/* Should only happen with really sucky default rc files... */
SETERR (E_CANTXPND);
return NOMACRO;
}
match = yetmatch = 0;
for (cur = mactab, s = mactabsize; s; cur++, s--) {
if (!cur->command)
continue; /* deleted macro */
if (!strcmp(cur->string, macro))
matched = cur, match++;
else if (!strncmp(cur->string, macro, strlen(macro)))
yetmatch++;
}
if (match == 1) {
if (yetmatch) {
SETERR (E_AMBIG);
return BADMACRO;
}
/* XXX it's not clear how to handle error when setting
* the number N --- this is a deficiency in the style of error-
* reporting suggested in command.c and less.h. Could have
* setvar() guarantee success when setting "number". A failure
* must not become fatal or it becomes impossible to do
* any commands at all. */
if (anyN) {
if (matched->flags & STICKYNUMB)
matched->defnumber = number;
(void) setvari("number", number);
} else
(void) setvari("number", matched->defnumber);
clear_error();
if (command(matched->command))
return BADCOMMAND;
return OK;
}
if (match > 1) {
SETERR (E_AMBIG);
return BADMACRO;
}
if (!match && !yetmatch) {
SETERR (E_CANTXPND);
return NOMACRO;
}
assert(yetmatch);
return TOOMACRO;
}
/*
* Associates a macro with a given command. Returns -1 if it was unable to
* set the macro. Errors associated with setting a macro may be caught
* either in this function, setmacro(), or in runmacro(). Both macro and
* command are strcpy()'d into their own space.
*/
int
setmacro(macro, command)
const char *macro;
const char *command;
{
struct macro *cur, *new = NULL;
char *new_mac, *new_com;
int s;
assert (macro); assert (command);
/* First, check for any existing macro matches in the custom table */
s = mactabsize;
for (cur = mactab; s; cur++, s--) {
if (!cur->command) {
/* Hmm... A deleted macro in the table */
new = cur;
continue;
}
if (!strcmp(cur->string, macro)) {
/*
* An exact match to the new macro already exists.
* Calling realloc() on cur->string and cur->command
* without risking being left in bad state is tricky.
* Just do it the slow but sure way...
*/
new = cur;
break;
}
}
/*
* Do the allocations here so that we can maintain consistent state
* even if realloc() fails when we try to expand the table (suppose
* the table gets expanded but the next malloc to get space for the
* macro fails).
*/
if (!FMALLOC(strlen(macro) + 1, new_mac))
return -1;
if (!FMALLOC(strlen(command) + 1, new_com))
return -1;
if (!new) {
/* Extend the command table by one record */
struct macro *t = realloc(mactab, (mactabsize + 1) *
sizeof(struct macro));
if (!t) {
/* The old mactab is still valid. Just back out. */
free(new_mac), free(new_com);
SETERR (E_MALLOC);
return -1;
} else
mactab = t;
new = &mactab[mactabsize];
mactabsize++;
new->string = new->command = NULL;
}
if (new->string) free(new->string);
if (new->command) free(new->command);
new->string = new_mac;
new->command = new_com;
strcpy(new->string, macro);
strcpy(new->command, command);
return 0;
}
/*
* Set the sticky tag on a macro. Returns -1 on failure, 0 on success.
*/
int
stickymac(macro, state)
const char *macro;
int state; /* set it to TRUE or set it to FALSE */
{
struct macro *m = matchmac(macro);
if (!m)
return -1;
if (state)
m->flags |= STICKYNUMB;
else
m->flags &= ~STICKYNUMB;
return 0;
}
/*
* Set the default number of a macro. Returns -1 on failure, 0 on success.
*/
int
setmacnumb(macro, N)
const char *macro;
long N; /* The default number */
{
struct macro *m = matchmac(macro);
if (!m)
return -1;
m->defnumber = N;
return 0;
}
/*
* Tries to find a struct macro matching "macro". Returns NULL if an exact
* match could not be found (eg. ambiguous macro, no macro, etc).
*/
static struct macro *
matchmac(macro)
const char *macro;
{
struct macro *retr, *cur;
int s;
retr = NULL;
for (cur = mactab, s = mactabsize; s; cur++, s--) {
if (!cur->command)
continue;
if (!strcmp(cur->string, macro)) {
if (retr) {
SETERR (E_AMBIG);
return NULL; /* matched twice! */
} else
retr = cur;
} else if (!strncmp(cur->string, macro, strlen(macro))) {
SETERR (E_AMBIG);
return NULL; /* ambiguous macro! */
}
}
return retr;
}