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freebsd/contrib/less/option.c
Paul Saab a5f0fb151d Import the [now] dual licensed version 3.5.4 of less. It is
distributed under your choice of the GPL or a BSD style license.

Reviewed by:	peter
Obtained from:	http://home.flash.net/~marknu/less/
2000-05-22 09:53:22 +00:00

611 lines
12 KiB
C

/*
* Copyright (C) 1984-2000 Mark Nudelman
*
* You may distribute under the terms of either the GNU General Public
* License or the Less License, as specified in the README file.
*
* For more information about less, or for information on how to
* contact the author, see the README file.
*/
/*
* Process command line options.
*
* Each option is a single letter which controls a program variable.
* The options have defaults which may be changed via
* the command line option, toggled via the "-" command,
* or queried via the "_" command.
*/
#include "less.h"
#include "option.h"
static struct option *pendopt;
public int plusoption = FALSE;
static char *propt();
static char *optstring();
static int flip_triple();
extern int screen_trashed;
extern char *every_first_cmd;
/*
* Scan an argument (either from the command line or from the
* LESS environment variable) and process it.
*/
public void
scan_option(s)
char *s;
{
register struct option *o;
register int optc;
char *optname;
char *printopt;
char *str;
int set_default;
int lc;
int err;
PARG parg;
if (s == NULL)
return;
/*
* If we have a pending option which requires an argument,
* handle it now.
* This happens if the previous option was, for example, "-P"
* without a following string. In that case, the current
* option is simply the argument for the previous option.
*/
if (pendopt != NULL)
{
switch (pendopt->otype & OTYPE)
{
case STRING:
(*pendopt->ofunc)(INIT, s);
break;
case NUMBER:
printopt = propt(pendopt->oletter);
*(pendopt->ovar) = getnum(&s, printopt, (int*)NULL);
break;
}
pendopt = NULL;
return;
}
set_default = FALSE;
optname = NULL;
while (*s != '\0')
{
/*
* Check some special cases first.
*/
switch (optc = *s++)
{
case ' ':
case '\t':
case END_OPTION_STRING:
continue;
case '-':
/*
* "--" indicates an option name instead of a letter.
*/
if (*s == '-')
{
optname = ++s;
break;
}
/*
* "-+" means set these options back to their defaults.
* (They may have been set otherwise by previous
* options.)
*/
set_default = (*s == '+');
if (set_default)
s++;
continue;
case '+':
/*
* An option prefixed by a "+" is ungotten, so
* that it is interpreted as less commands
* processed at the start of the first input file.
* "++" means process the commands at the start of
* EVERY input file.
*/
plusoption = TRUE;
if (*s == '+')
every_first_cmd = save(++s);
else
ungetsc(s);
s = optstring(s, propt('+'));
continue;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
/*
* Special "more" compatibility form "-<number>"
* instead of -z<number> to set the scrolling
* window size.
*/
s--;
optc = 'z';
break;
}
/*
* Not a special case.
* Look up the option letter in the option table.
*/
err = 0;
if (optname == NULL)
{
printopt = propt(optc);
lc = SIMPLE_IS_LOWER(optc);
o = findopt(optc);
} else
{
printopt = optname;
lc = SIMPLE_IS_LOWER(optname[0]);
o = findopt_name(&optname, NULL, &err);
s = optname;
optname = NULL;
if (*s == '\0' || *s == ' ')
{
/*
* The option name matches exactly.
*/
;
} else if (*s == '=')
{
/*
* The option name is followed by "=value".
*/
if (o != NULL &&
(o->otype & OTYPE) != STRING &&
(o->otype & OTYPE) != NUMBER)
{
parg.p_string = printopt;
error("The %s option should not be followed by =",
&parg);
quit(QUIT_ERROR);
}
s++;
} else
{
/*
* The specified name is longer than the
* real option name.
*/
o = NULL;
}
}
if (o == NULL)
{
parg.p_string = printopt;
if (err == OPT_AMBIG)
error("%s is an ambiguous abbreviation (\"less --help\" for help)",
&parg);
else
error("There is no %s option (\"less --help\" for help)",
&parg);
quit(QUIT_ERROR);
}
str = NULL;
switch (o->otype & OTYPE)
{
case BOOL:
if (set_default)
*(o->ovar) = o->odefault;
else
*(o->ovar) = ! o->odefault;
break;
case TRIPLE:
if (set_default)
*(o->ovar) = o->odefault;
else
*(o->ovar) = flip_triple(o->odefault, lc);
break;
case STRING:
if (*s == '\0')
{
/*
* Set pendopt and return.
* We will get the string next time
* scan_option is called.
*/
pendopt = o;
return;
}
/*
* Don't do anything here.
* All processing of STRING options is done by
* the handling function.
*/
str = s;
s = optstring(s, printopt);
break;
case NUMBER:
if (*s == '\0')
{
pendopt = o;
return;
}
*(o->ovar) = getnum(&s, printopt, (int*)NULL);
break;
}
/*
* If the option has a handling function, call it.
*/
if (o->ofunc != NULL)
(*o->ofunc)(INIT, str);
}
}
/*
* Toggle command line flags from within the program.
* Used by the "-" and "_" commands.
* how_toggle may be:
* OPT_NO_TOGGLE just report the current setting, without changing it.
* OPT_TOGGLE invert the current setting
* OPT_UNSET set to the default value
* OPT_SET set to the inverse of the default value
*/
public void
toggle_option(c, s, how_toggle)
int c;
char *s;
int how_toggle;
{
register struct option *o;
register int num;
int no_prompt;
int err;
PARG parg;
no_prompt = (how_toggle & OPT_NO_PROMPT);
how_toggle &= ~OPT_NO_PROMPT;
/*
* Look up the option letter in the option table.
*/
o = findopt(c);
if (o == NULL)
{
parg.p_string = propt(c);
error("There is no %s option", &parg);
return;
}
if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE))
{
parg.p_string = propt(c);
error("Cannot change the %s option", &parg);
return;
}
if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY))
{
parg.p_string = propt(c);
error("Cannot query the %s option", &parg);
return;
}
/*
* Check for something which appears to be a do_toggle
* (because the "-" command was used), but really is not.
* This could be a string option with no string, or
* a number option with no number.
*/
switch (o->otype & OTYPE)
{
case STRING:
case NUMBER:
if (how_toggle == OPT_TOGGLE && *s == '\0')
how_toggle = OPT_NO_TOGGLE;
break;
}
#if HILITE_SEARCH
if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
repaint_hilite(0);
#endif
/*
* Now actually toggle (change) the variable.
*/
if (how_toggle != OPT_NO_TOGGLE)
{
switch (o->otype & OTYPE)
{
case BOOL:
/*
* Boolean.
*/
switch (how_toggle)
{
case OPT_TOGGLE:
*(o->ovar) = ! *(o->ovar);
break;
case OPT_UNSET:
*(o->ovar) = o->odefault;
break;
case OPT_SET:
*(o->ovar) = ! o->odefault;
break;
}
break;
case TRIPLE:
/*
* Triple:
* If user gave the lower case letter, then switch
* to 1 unless already 1, in which case make it 0.
* If user gave the upper case letter, then switch
* to 2 unless already 2, in which case make it 0.
*/
switch (how_toggle)
{
case OPT_TOGGLE:
*(o->ovar) = flip_triple(*(o->ovar),
islower(c));
break;
case OPT_UNSET:
*(o->ovar) = o->odefault;
break;
case OPT_SET:
*(o->ovar) = flip_triple(o->odefault,
islower(c));
break;
}
break;
case STRING:
/*
* String: don't do anything here.
* The handling function will do everything.
*/
switch (how_toggle)
{
case OPT_SET:
case OPT_UNSET:
error("Cannot use \"-+\" or \"--\" for a string option",
NULL_PARG);
return;
}
break;
case NUMBER:
/*
* Number: set the variable to the given number.
*/
switch (how_toggle)
{
case OPT_TOGGLE:
num = getnum(&s, '\0', &err);
if (!err)
*(o->ovar) = num;
break;
case OPT_UNSET:
*(o->ovar) = o->odefault;
break;
case OPT_SET:
error("Can't use \"-!\" for a numeric option",
NULL_PARG);
return;
}
break;
}
}
/*
* Call the handling function for any special action
* specific to this option.
*/
if (o->ofunc != NULL)
(*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s);
#if HILITE_SEARCH
if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
chg_hilite();
#endif
if (!no_prompt)
{
/*
* Print a message describing the new setting.
*/
switch (o->otype & OTYPE)
{
case BOOL:
case TRIPLE:
/*
* Print the odesc message.
*/
error(o->odesc[*(o->ovar)], NULL_PARG);
break;
case NUMBER:
/*
* The message is in odesc[1] and has a %d for
* the value of the variable.
*/
parg.p_int = *(o->ovar);
error(o->odesc[1], &parg);
break;
case STRING:
/*
* Message was already printed by the handling function.
*/
break;
}
}
if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT))
screen_trashed = TRUE;
}
/*
* "Toggle" a triple-valued option.
*/
static int
flip_triple(val, lc)
int val;
int lc;
{
if (lc)
return ((val == OPT_ON) ? OPT_OFF : OPT_ON);
else
return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS);
}
/*
* Return a string suitable for printing as the "name" of an option.
* For example, if the option letter is 'x', just return "-x".
*/
static char *
propt(c)
int c;
{
static char buf[8];
sprintf(buf, "-%s", prchar(c));
return (buf);
}
/*
* Determine if an option is a single character option (BOOL or TRIPLE),
* or if it a multi-character option (NUMBER).
*/
public int
single_char_option(c)
int c;
{
register struct option *o;
o = findopt(c);
if (o == NULL)
return (TRUE);
return ((o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE)) != 0);
}
/*
* Return the prompt to be used for a given option letter.
* Only string and number valued options have prompts.
*/
public char *
opt_prompt(c)
int c;
{
register struct option *o;
o = findopt(c);
if (o == NULL || (o->otype & (STRING|NUMBER)) == 0)
return (NULL);
return (o->odesc[0]);
}
/*
* Return whether or not there is a string option pending;
* that is, if the previous option was a string-valued option letter
* (like -P) without a following string.
* In that case, the current option is taken to be the string for
* the previous option.
*/
public int
isoptpending()
{
return (pendopt != NULL);
}
/*
* Print error message about missing string.
*/
static void
nostring(printopt)
char *printopt;
{
PARG parg;
parg.p_string = printopt;
error("Value is required after %s", &parg);
}
/*
* Print error message if a STRING type option is not followed by a string.
*/
public void
nopendopt()
{
nostring(propt(pendopt->oletter));
}
/*
* Scan to end of string or to an END_OPTION_STRING character.
* In the latter case, replace the char with a null char.
* Return a pointer to the remainder of the string, if any.
*/
static char *
optstring(s, printopt)
char *s;
char *printopt;
{
register char *p;
if (*s == '\0')
{
nostring(printopt);
quit(QUIT_ERROR);
}
for (p = s; *p != '\0'; p++)
if (*p == END_OPTION_STRING)
{
*p = '\0';
return (p+1);
}
return (p);
}
/*
* Translate a string into a number.
* Like atoi(), but takes a pointer to a char *, and updates
* the char * to point after the translated number.
*/
public int
getnum(sp, printopt, errp)
char **sp;
char *printopt;
int *errp;
{
register char *s;
register int n;
register int neg;
PARG parg;
s = skipsp(*sp);
neg = FALSE;
if (*s == '-')
{
neg = TRUE;
s++;
}
if (*s < '0' || *s > '9')
{
if (errp != NULL)
{
*errp = TRUE;
return (-1);
}
parg.p_string = printopt;
error("Number is required after %s", &parg);
quit(QUIT_ERROR);
}
n = 0;
while (*s >= '0' && *s <= '9')
n = 10 * n + *s++ - '0';
*sp = s;
if (errp != NULL)
*errp = FALSE;
if (neg)
n = -n;
return (n);
}