/*
* 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.
*/
/*
* Prompting and other messages.
* There are three flavors of prompts, SHORT, MEDIUM and LONG,
* selected by the -m/-M options.
* There is also the "equals message", printed by the = command.
* A prompt is a message composed of various pieces, such as the
* name of the file being viewed, the percentage into the file, etc.
*/
#include "less.h"
#include "position.h"
extern int pr_type;
extern int new_file;
extern int sc_width;
extern int so_s_width, so_e_width;
extern int linenums;
extern int hshift;
extern int sc_height;
extern int jump_sline;
extern int less_is_more;
extern int header_lines;
extern IFILE curr_ifile;
#if EDITOR
extern char *editor;
extern char *editproto;
#endif
/*
* Prototypes for the three flavors of prompts.
* These strings are expanded by pr_expand().
*/
static constant char s_proto[] =
"?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t";
static constant char m_proto[] =
"?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
static constant char M_proto[] =
"?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
static constant char e_proto[] =
"?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
static constant char h_proto[] =
"HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
static constant char w_proto[] =
"Waiting for data";
static constant char more_proto[] =
"--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)";
public char constant *prproto[3];
public char constant *eqproto = e_proto;
public char constant *hproto = h_proto;
public char constant *wproto = w_proto;
/*
* Append a string to the end of the message.
*/
static void ap_str(char *s)
{
int len;
len = (int) strlen(s);
if (mp + len >= message + PROMPT_SIZE)
len = (int) (message + PROMPT_SIZE - mp - 1);
strncpy(mp, s, len);
mp += len;
*mp = '\0';
}
/*
* Append a character to the end of the message.
*/
static void ap_char(char c)
{
char buf[2];
buf[0] = c;
buf[1] = '\0';
ap_str(buf);
}
/*
* Append a POSITION (as a decimal integer) to the end of the message.
*/
static void ap_pos(POSITION pos)
{
char buf[INT_STRLEN_BOUND(pos) + 2];
postoa(pos, buf, 10);
ap_str(buf);
}
/*
* Append a line number to the end of the message.
*/
static void ap_linenum(LINENUM linenum)
{
char buf[INT_STRLEN_BOUND(linenum) + 2];
linenumtoa(linenum, buf, 10);
ap_str(buf);
}
/*
* Append an integer to the end of the message.
*/
static void ap_int(int num)
{
char buf[INT_STRLEN_BOUND(num) + 2];
inttoa(num, buf, 10);
ap_str(buf);
}
/*
* Append a question mark to the end of the message.
*/
static void ap_quest(void)
{
ap_str("?");
}
/*
* Return the "current" byte offset in the file.
*/
static POSITION curr_byte(int where)
{
POSITION pos;
pos = position(where);
while (pos == NULL_POSITION && where >= 0 && where < sc_height-1)
pos = position(++where);
if (pos == NULL_POSITION)
pos = ch_length();
return (pos);
}
/*
* Return the value of a prototype conditional.
* A prototype string may include conditionals which consist of a
* question mark followed by a single letter.
* Here we decode that letter and return the appropriate boolean value.
*/
static int cond(char c, int where)
{
POSITION len;
switch (c)
{
case 'a': /* Anything in the message yet? */
return (mp > message);
case 'b': /* Current byte offset known? */
return (curr_byte(where) != NULL_POSITION);
case 'c':
return (hshift != 0);
case 'e': /* At end of file? */
return (eof_displayed());
case 'f': /* Filename known? */
case 'g':
return (strcmp(get_filename(curr_ifile), "-") != 0);
case 'l': /* Line number known? */
case 'd': /* Same as l */
if (!linenums)
return 0;
return (currline(where) != 0);
case 'L': /* Final line number known? */
case 'D': /* Final page number known? */
return (linenums && ch_length() != NULL_POSITION);
case 'm': /* More than one file? */
#if TAGS
return (ntags() ? (ntags() > 1) : (nifile() > 1));
#else
return (nifile() > 1);
#endif
case 'n': /* First prompt in a new file? */
#if TAGS
return (ntags() ? 1 : new_file);
#else
return (new_file);
#endif
case 'p': /* Percent into file (bytes) known? */
return (curr_byte(where) != NULL_POSITION &&
ch_length() > 0);
case 'P': /* Percent into file (lines) known? */
return (currline(where) != 0 &&
(len = ch_length()) > 0 &&
find_linenum(len) != 0);
case 's': /* Size of file known? */
case 'B':
return (ch_length() != NULL_POSITION);
case 'x': /* Is there a "next" file? */
#if TAGS
if (ntags())
return (0);
#endif
return (next_ifile(curr_ifile) != NULL_IFILE);
}
return (0);
}
/*
* Decode a "percent" prototype character.
* A prototype string may include various "percent" escapes;
* that is, a percent sign followed by a single letter.
* Here we decode that letter and take the appropriate action,
* usually by appending something to the message being built.
*/
static void protochar(int c, int where, int iseditproto)
{
POSITION pos;
POSITION len;
int n;
LINENUM linenum;
LINENUM last_linenum;
IFILE h;
char *s;
switch (c)
{
case 'b': /* Current byte offset */
pos = curr_byte(where);
if (pos != NULL_POSITION)
ap_pos(pos);
else
ap_quest();
break;
case 'c':
ap_int(hshift);
break;
case 'd': /* Current page number */
linenum = currline(where);
if (linenum > 0 && sc_height > header_lines + 1)
ap_linenum(PAGE_NUM(linenum));
else
ap_quest();
break;
case 'D': /* Final page number */
/* Find the page number of the last byte in the file (len-1). */
len = ch_length();
if (len == NULL_POSITION)
ap_quest();
else if (len == 0)
/* An empty file has no pages. */
ap_linenum(0);
else
{
linenum = find_linenum(len - 1);
if (linenum <= 0)
ap_quest();
else
ap_linenum(PAGE_NUM(linenum));
}
break;
#if EDITOR
case 'E': /* Editor name */
ap_str(editor);
break;
#endif
case 'f': /* File name */
ap_str(get_filename(curr_ifile));
break;
case 'F': /* Last component of file name */
ap_str(last_component(get_filename(curr_ifile)));
break;
case 'g': /* Shell-escaped file name */
s = shell_quote(get_filename(curr_ifile));
ap_str(s);
free(s);
break;
case 'i': /* Index into list of files */
#if TAGS
if (ntags())
ap_int(curr_tag());
else
#endif
ap_int(get_index(curr_ifile));
break;
case 'l': /* Current line number */
linenum = currline(where);
if (linenum != 0)
ap_linenum(vlinenum(linenum));
else
ap_quest();
break;
case 'L': /* Final line number */
len = ch_length();
if (len == NULL_POSITION || len == ch_zero() ||
(linenum = find_linenum(len)) <= 0)
ap_quest();
else
ap_linenum(vlinenum(linenum-1));
break;
case 'm': /* Number of files */
#if TAGS
n = ntags();
if (n)
ap_int(n);
else
#endif
ap_int(nifile());
break;
case 'p': /* Percent into file (bytes) */
pos = curr_byte(where);
len = ch_length();
if (pos != NULL_POSITION && len > 0)
ap_int(percentage(pos,len));
else
ap_quest();
break;
case 'P': /* Percent into file (lines) */
linenum = currline(where);
if (linenum == 0 ||
(len = ch_length()) == NULL_POSITION || len == ch_zero() ||
(last_linenum = find_linenum(len)) <= 0)
ap_quest();
else
ap_int(percentage(linenum, last_linenum));
break;
case 's': /* Size of file */
case 'B':
len = ch_length();
if (len != NULL_POSITION)
ap_pos(len);
else
ap_quest();
break;
case 't': /* Truncate trailing spaces in the message */
while (mp > message && mp[-1] == ' ')
mp--;
*mp = '\0';
break;
case 'T': /* Type of list */
#if TAGS
if (ntags())
ap_str("tag");
else
#endif
ap_str("file");
break;
case 'x': /* Name of next file */
h = next_ifile(curr_ifile);
if (h != NULL_IFILE)
ap_str(get_filename(h));
else
ap_quest();
break;
}
}
/*
* Skip a false conditional.
* When a false condition is found (either a false IF or the ELSE part
* of a true IF), this routine scans the prototype string to decide
* where to resume parsing the string.
* We must keep track of nested IFs and skip them properly.
*/
static constant char * skipcond(constant char *p)
{
int iflevel;
/*
* We came in here after processing a ? or :,
* so we start nested one level deep.
*/
iflevel = 1;
for (;;) switch (*++p)
{
case '?':
/*
* Start of a nested IF.
*/
iflevel++;
break;
case ':':
/*
* Else.
* If this matches the IF we came in here with,
* then we're done.
*/
if (iflevel == 1)
return (p);
break;
case '.':
/*
* Endif.
* If this matches the IF we came in here with,
* then we're done.
*/
if (--iflevel == 0)
return (p);
break;
case '\\':
/*
* Backslash escapes the next character.
*/
if (p[1] != '\0')
++p;
break;
case '\0':
/*
* Whoops. Hit end of string.
* This is a malformed conditional, but just treat it
* as if all active conditionals ends here.
*/
return (p-1);
}
/*NOTREACHED*/
}
/*
* Decode a char that represents a position on the screen.
*/
static constant char * wherechar(char constant *p, int *wp)
{
switch (*p)
{
case 'b': case 'd': case 'l': case 'p': case 'P':
switch (*++p)
{
case 't': *wp = TOP; break;
case 'm': *wp = MIDDLE; break;
case 'b': *wp = BOTTOM; break;
case 'B': *wp = BOTTOM_PLUS_ONE; break;
case 'j': *wp = sindex_from_sline(jump_sline); break;
default: *wp = TOP; p--; break;
}
}
return (p);
}
/*
* Construct a message based on a prototype string.
*/
public char * pr_expand(constant char *proto)
{
constant char *p;
int c;
int where;
mp = message;
if (*proto == '\0')
return ("");
for (p = proto; *p != '\0'; p++)
{
switch (*p)
{
default: /* Just put the character in the message */
ap_char(*p);
break;
case '\\': /* Backslash escapes the next character */
if (p[1] != '\0')
ap_char(*++p);
break;
case '?': /* Conditional (IF) */
if ((c = *++p) == '\0')
--p;
else
{
where = 0;
p = wherechar(p, &where);
if (!cond(c, where))
p = skipcond(p);
}
break;
case ':': /* ELSE */
p = skipcond(p);
break;
case '.': /* ENDIF */
break;
case '%': /* Percent escape */
if ((c = *++p) == '\0')
--p;
else
{
where = 0;
p = wherechar(p, &where);
protochar(c, where,
#if EDITOR
(proto == editproto));
#else
0);
#endif
}
break;
}
}
if (mp == message)
return ("");
return (message);
}
/*
* Return a message suitable for printing by the "=" command.
*/
public char * eq_message(void)
{
return (pr_expand(eqproto));
}
/*
* Return a prompt.
* This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
* If we can't come up with an appropriate prompt, return NULL
* and the caller will prompt with a colon.
*/
public char * pr_string(void)
{
char *prompt;
int type;
