/*
* Copyright (C) 1984-2023 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, 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 loption *pendopt;
public int plusoption = FALSE;
static char *optstring(char *s, char **p_str, char *printopt, char *validchars);
static int flip_triple(int val, int lc);
extern int screen_trashed;
extern int less_is_more;
extern int quit_at_eof;
extern char *every_first_cmd;
extern int opt_use_backslash;
/*
* Return a printable description of an option.
*/
static char * opt_desc(struct loption *o)
{
static char buf[OPTNAME_MAX + 10];
if (o->oletter == OLETTER_NONE)
SNPRINTF1(buf, sizeof(buf), "--%s", o->onames->oname);
else
SNPRINTF2(buf, sizeof(buf), "-%c (--%s)", o->oletter, o->onames->oname);
return (buf);
}
/*
* Return a string suitable for printing as the "name" of an option.
* For example, if the option letter is 'x', just return "-x".
*/
public char * propt(int c)
{
static char buf[MAX_PRCHAR_LEN+2];
sprintf(buf, "-%s", prchar(c));
return (buf);
}
/*
* Scan an argument (either from the command line or from the
* LESS environment variable) and process it.
*/
public void scan_option(char *s)
{
struct loption *o;
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 = opt_desc(pendopt);
*(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;
s = optstring(s, &str, propt('+'), NULL);
if (s == NULL)
return;
if (*str == '+')
{
if (every_first_cmd != NULL)
free(every_first_cmd);
every_first_cmd = save(str+1);
} else
{
ungetsc(str);
ungetcc_back(CHAR_END_COMMAND);
}
free(str);
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;
case 'n':
if (less_is_more)
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 = ASCII_IS_LOWER(optc);
o = findopt(optc);
} else
{
printopt = optname;
lc = ASCII_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);
return;
}
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);
return;
}
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.
*/
while (*s == ' ')
s++;
s = optstring(s, &str, printopt, o->odesc[1]);
if (s == NULL)
return;
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);
if (str != NULL)
free(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(struct loption *o, int lower, char *s, int how_toggle)
{
int num;
int no_prompt;
int err;
PARG parg;
if (o == NULL)
{
error("No such option", NULL_PARG);
return;
}
if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE))
{
parg.p_string = opt_desc(o);
error("Cannot change the %s option", &parg);
return;
}
if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY))
{
parg.p_string = opt_desc(o);
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;
}
/*
* 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), lower);
break;
case OPT_UNSET:
*(o->ovar) = o->odefault;
break;
case OPT_SET:
*(o->ovar) = flip_triple(o->odefault, lower);
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, NULL, &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 (!no_prompt)
{
/*
* Print a message describing the new setting.
*/
switch (o->otype & OTYPE)
{
case BOOL:
case TRIPLE:
if (*(o->ovar) < 0)
error("Negative option is invalid", NULL_PARG);
/*
* 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;
}
}
/*
* "Toggle" a triple-valued option.
*/
static int flip_triple(int val, int lc)
{
if (lc)
return ((val == OPT_ON) ? OPT_OFF : OPT_ON);
else
return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS);
}
/*
* Determine if an option takes a parameter.
*/
public int opt_has_param(struct loption *o)
{
if (o == NULL)
return (0);
if (o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE))
return (0);
return (1);
}
/*
* Return the prompt to be used for a given option letter.
* Only string and number valued options have prompts.
*/
public char * opt_prompt(struct loption *o)
{
if (o == NULL || (o->otype & (STRING|NUMBER)) == 0)
return ("?");
return (o->odesc[0]);
}
/*
* If the specified option can be toggled, return NULL.
* Otherwise return an appropriate error message.
*/
public char * opt_toggle_disallowed(int c)
{
switch (c)
{
case 'o':
if (ch_getflags() & CH_CANSEEK)
return "Input is not a pipe";
break;
}
return NULL;
}
/*
* 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(void)
{
return (pendopt != NULL);
}
/*
* Print error message about missing string.
*/
static void nostring(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(void)
{
nostring(opt_desc(pendopt));
}
/*
* 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(char *s, char **p_str, char *printopt, char *validchars)
{
char *p;
char *out;
if (*s == '\0')
{
nostring(printopt);
return (NULL);
}
/* Alloc could be more than needed, but not worth trimming. */
*p_str = (char *) ecalloc(strlen(s)+1, sizeof(char));
out = *p_str;
for (p = s; *p != '\0'; p++)
{
if (opt_use_backslash && *p == '\\' && p[1] != '\0')
{
/* Take next char literally. */
++p;
} else
{
if (*p == END_OPTION_STRING ||
(validchars != NULL && strchr(validchars, *p) == NULL))
/* End of option string. */
break;
}
*out++ = *p;
}
*out = '\0';
return (p);
}
/*
*/
static int num_error(char *printopt, int *errp, int overflow)
{
PARG parg;
if (errp != NULL)
{
*errp = TRUE;
return (-1);
}
if (printopt != NULL)
{
parg.p_string = printopt;
error((overflow
? "Number too large in '%s'"
: "Number is required after %s"),
&parg);
}
return (-1);
}
/*
* 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(char **sp, char *printopt, int *errp)
{
char *s;
int n;
int neg;
s = skipsp(*sp);
neg = FALSE;
if (*s == '-')
{
neg = TRUE;
s++;
}
if (*s < '0' || *s > '9')
return (num_error(printopt, errp, FALSE));
n = lstrtoi(s, sp, 10);
if (n < 0)
return (num_error(printopt, errp, TRUE));
if (errp != NULL)
*errp = FALSE;
if (neg)
n = -n;
return (n);
}
/*
* Translate a string into a fraction, represented by the part of a
* number which would follow a decimal point.
* The value of the fraction is returned as parts per NUM_FRAC_DENOM.
* That is, if "n" is returned, the fraction intended is n/NUM_FRAC_DENOM.
*/
public long getfraction(char **sp, char *printopt, int *errp)
{
char *s;
long frac = 0;
int fraclen = 0;
s = skipsp(*sp);
if (*s < '0' || *s > '9')
return (num_error(printopt, errp, FALSE));
/*
* Get the value of the -e flag.
*/
public int get_quit_at_eof(void)
{
if (!less_is_more)
return quit_at_eof;
/* When less_is_more is set, the -e flag semantics are different. */
return quit_at_eof ? OPT_ONPLUS : OPT_ON;
}
