/*
* 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.
*/
#include "less.h"
#include "position.h"
#if HAVE_STAT
#include <sys/stat.h>
#endif
#if HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
/* #if OS2 XXX should add a HAVE_SIGNAL_H */
#include <signal.h>
/* #endif XXX should add a HAVE_SIGNAL_H */
public int fd0 = 0;
extern int new_file;
extern int cbufs;
extern char *every_first_cmd;
extern int force_open;
extern int is_tty;
extern int sigs;
extern int hshift;
extern int want_filesize;
extern int consecutive_nulls;
extern int modelines;
extern int show_preproc_error;
extern IFILE curr_ifile;
extern IFILE old_ifile;
extern struct scrpos initial_scrpos;
extern void *ml_examine;
#if SPACES_IN_FILENAMES
extern char openquote;
extern char closequote;
#endif
#if LOGFILE
extern int logfile;
extern int force_logfile;
extern char *namelogfile;
#endif
#if HAVE_STAT_INO
public dev_t curr_dev;
public ino_t curr_ino;
#endif
/*
* Textlist functions deal with a list of words separated by spaces.
* init_textlist sets up a textlist structure.
* forw_textlist uses that structure to iterate thru the list of
* words, returning each one as a standard null-terminated string.
* back_textlist does the same, but runs thru the list backwards.
*/
public void init_textlist(struct textlist *tlist, char *str)
{
char *s;
#if SPACES_IN_FILENAMES
int meta_quoted = 0;
int delim_quoted = 0;
char *esc = get_meta_escape();
int esclen = (int) strlen(esc);
#endif
tlist->string = skipsp(str);
tlist->endstring = tlist->string + strlen(tlist->string);
for (s = str; s < tlist->endstring; s++)
{
#if SPACES_IN_FILENAMES
if (meta_quoted)
{
meta_quoted = 0;
} else if (esclen > 0 && s + esclen < tlist->endstring &&
strncmp(s, esc, esclen) == 0)
{
meta_quoted = 1;
s += esclen - 1;
} else if (delim_quoted)
{
if (*s == closequote)
delim_quoted = 0;
} else /* (!delim_quoted) */
{
if (*s == openquote)
delim_quoted = 1;
else if (*s == ' ')
*s = '\0';
}
#else
if (*s == ' ')
*s = '\0';
#endif
}
}
/*
* prev == NULL means return the first word in the list.
* Otherwise, return the word after "prev".
*/
if (prev == NULL)
s = tlist->string;
else
s = prev + strlen(prev);
if (s >= tlist->endstring)
return (NULL);
while (*s == '\0')
s++;
if (s >= tlist->endstring)
return (NULL);
return (s);
}
/*
* prev == NULL means return the last word in the list.
* Otherwise, return the word before "prev".
*/
if (prev == NULL)
s = tlist->endstring;
else if (prev <= tlist->string)
return (NULL);
else
s = prev - 1;
while (*s == '\0')
s--;
if (s <= tlist->string)
return (NULL);
while (s[-1] != '\0' && s > tlist->string)
s--;
return (s);
}
/*
* String length, terminated by option separator (space or colon).
* Space/colon can be escaped with backspace.
*/
static int modeline_option_len(char *str)
{
int esc = FALSE;
char *s;
for (s = str; *s != '\0'; s++)
{
if (esc)
esc = FALSE;
else if (*s == '\\')
esc = TRUE;
else if (*s == ' ' || *s == ':') /* separator */
break;
}
return (s - str);
}
/*
* Parse colon- or space-separated option settings in a modeline.
*/
static void modeline_options(char *str, char end_char)
{
for (;;)
{
int opt_len;
str = skipsp(str);
if (*str == '\0' || *str == end_char)
break;
opt_len = modeline_option_len(str);
modeline_option(str, opt_len);
str += opt_len;
if (*str != '\0')
str += 1; /* skip past the separator */
}
}
/*
* See if there is a modeline string in a line.
*/
static void check_modeline(char *line)
{
#if HAVE_STRSTR
static char *pgms[] = { "less:", "vim:", "vi:", "ex:", NULL };
char **pgm;
for (pgm = pgms; *pgm != NULL; ++pgm)
{
char *pline = line;
for (;;)
{
char *str;
pline = strstr(pline, *pgm);
if (pline == NULL) /* pgm is not in this line */
break;
str = skipsp(pline + strlen(*pgm));
if (pline == line || pline[-1] == ' ')
{
if (strncmp(str, "set ", 4) == 0)
modeline_options(str+4, ':');
else if (pgm != &pgms[0]) /* "less:" requires "set" */
modeline_options(str, '\0');
break;
}
/* Continue searching the rest of the line. */
pline = str;
}
}
#endif /* HAVE_STRSTR */
}
/*
* Read lines from start of file and check if any are modelines.
*/
static void check_modelines(void)
{
POSITION pos = ch_zero();
int i;
for (i = 0; i < modelines; i++)
{
char *line;
int line_len;
if (ABORT_SIGS())
return;
pos = forw_raw_line(pos, &line, &line_len);
if (pos == NULL_POSITION)
break;
check_modeline(line);
}
}
/*
* Close a pipe opened via popen.
*/
static void close_pipe(FILE *pipefd)
{
int status;
PARG parg;
if (pipefd == NULL)
return;
#if OS2
/*
* The pclose function of OS/2 emx sometimes fails.
* Send SIGINT to the piped process before closing it.
*/
kill(pipefd->_pid, SIGINT);
#endif
status = pclose(pipefd);
if (status == -1)
{
/* An internal error in 'less', not a preprocessor error. */
parg.p_string = errno_message("pclose");
error("%s", &parg);
free(parg.p_string);
return;
}
if (!show_preproc_error)
return;
#if defined WIFEXITED && defined WEXITSTATUS
if (WIFEXITED(status))
{
int s = WEXITSTATUS(status);
if (s != 0)
{
parg.p_int = s;
error("Input preprocessor failed (status %d)", &parg);
}
return;
}
#endif
#if defined WIFSIGNALED && defined WTERMSIG && HAVE_STRSIGNAL
if (WIFSIGNALED(status))
{
int sig = WTERMSIG(status);
if (sig != SIGPIPE || ch_length() != NULL_POSITION)
{
parg.p_string = signal_message(sig);
error("Input preprocessor terminated: %s", &parg);
}
return;
}
#endif
if (status != 0)
{
parg.p_int = status;
error("Input preprocessor exited with status %x", &parg);
}
}
/*
* Drain and close an input pipe if needed.
*/
public void close_altpipe(IFILE ifile)
{
FILE *altpipe = get_altpipe(ifile);
if (altpipe != NULL && !(ch_getflags() & CH_KEEPOPEN))
{
close_pipe(altpipe);
set_altpipe(ifile, NULL);
}
}
/*
* Check for error status from the current altpipe.
* May or may not close the pipe.
*/
public void check_altpipe_error(void)
{
if (!show_preproc_error)
return;
if (curr_ifile != NULL_IFILE && get_altfilename(curr_ifile) != NULL)
close_altpipe(curr_ifile);
}
/*
* Close the current input file.
*/
static void close_file(void)
{
struct scrpos scrpos;
char *altfilename;
if (curr_ifile == NULL_IFILE)
return;
/*
* Save the current position so that we can return to
* the same position if we edit this file again.
*/
get_scrpos(&scrpos, TOP);
if (scrpos.pos != NULL_POSITION)
{
store_pos(curr_ifile, &scrpos);
lastmark();
}
/*
* Close the file descriptor, unless it is a pipe.
*/
ch_close();
/*
* If we opened a file using an alternate name,
* do special stuff to close it.
*/
altfilename = get_altfilename(curr_ifile);
if (altfilename != NULL)
{
close_altpipe(curr_ifile);
close_altfile(altfilename, get_filename(curr_ifile));
set_altfilename(curr_ifile, NULL);
}
curr_ifile = NULL_IFILE;
#if HAVE_STAT_INO
curr_ino = curr_dev = 0;
#endif
}
/*
* Edit a new file (given its name).
* Filename == "-" means standard input.
* Filename == NULL means just close the current file.
*/
public int edit(char *filename)
{
if (filename == NULL)
return (edit_ifile(NULL_IFILE));
return (edit_ifile(get_ifile(filename, curr_ifile)));
}
/*
* Clean up what edit_ifile did before error return.
*/
static int edit_error(char *filename, char *alt_filename, void *altpipe, IFILE ifile, IFILE was_curr_ifile)
{
if (alt_filename != NULL)
{
close_pipe(altpipe);
close_altfile(alt_filename, filename);
free(alt_filename);
}
del_ifile(ifile);
free(filename);
/*
* Re-open the current file.
*/
if (was_curr_ifile == ifile)
{
/*
* Whoops. The "current" ifile is the one we just deleted.
* Just give up.
*/
quit(QUIT_ERROR);
}
reedit_ifile(was_curr_ifile);
return (1);
}
/*
* Edit a new file (given its IFILE).
* ifile == NULL means just close the current file.
*/
public int edit_ifile(IFILE ifile)
{
int f;
int answer;
int chflags;
char *filename;
char *open_filename;
char *alt_filename;
void *altpipe;
IFILE was_curr_ifile;
PARG parg;
if (ifile == curr_ifile)
{
/*
* Already have the correct file open.
*/
return (0);
}
/*
* We must close the currently open file now.
* This is necessary to make the open_altfile/close_altfile pairs
* nest properly (or rather to avoid nesting at all).
* {{ Some stupid implementations of popen() mess up if you do:
* fA = popen("A"); fB = popen("B"); pclose(fA); pclose(fB); }}
*/
#if LOGFILE
end_logfile();
#endif
was_curr_ifile = save_curr_ifile();
if (curr_ifile != NULL_IFILE)
{
chflags = ch_getflags();
close_file();
if ((chflags & CH_HELPFILE) && held_ifile(was_curr_ifile) <= 1)
{
/*
* Don't keep the help file in the ifile list.
*/
del_ifile(was_curr_ifile);
was_curr_ifile = old_ifile;
}
}
if (ifile == NULL_IFILE)
{
/*
* No new file to open.
* (Don't set old_ifile, because if you call edit_ifile(NULL),
* you're supposed to have saved curr_ifile yourself,
* and you'll restore it if necessary.)
*/
unsave_ifile(was_curr_ifile);
return (0);
}
filename = save(get_filename(ifile));
/*
* See if LESSOPEN specifies an "alternate" file to open.
*/
altpipe = get_altpipe(ifile);
if (altpipe != NULL)
{
/*
* File is already open.
* chflags and f are not used by ch_init if ifile has
* filestate which should be the case if we're here.
* Set them here to avoid uninitialized variable warnings.
*/
chflags = 0;
f = -1;
alt_filename = get_altfilename(ifile);
open_filename = (alt_filename != NULL) ? alt_filename : filename;
} else
{
if (strcmp(filename, FAKE_HELPFILE) == 0 ||
strcmp(filename, FAKE_EMPTYFILE) == 0)
alt_filename = NULL;
else
alt_filename = open_altfile(filename, &f, &altpipe);
chflags = 0;
if (altpipe != NULL)
{
/*
* The alternate "file" is actually a pipe.
* f has already been set to the file descriptor of the pipe
* in the call to open_altfile above.
* Keep the file descriptor open because it was opened
* via popen(), and pclose() wants to close it.
*/
chflags |= CH_POPENED;
if (strcmp(filename, "-") == 0)
chflags |= CH_KEEPOPEN;
} else if (strcmp(filename, "-") == 0)
{
/*
* Use standard input.
* Keep the file descriptor open because we can't reopen it.
*/
f = fd0;
chflags |= CH_KEEPOPEN;
/*
* Must switch stdin to BINARY mode.
*/
SET_BINARY(f);
#if MSDOS_COMPILER==DJGPPC
/*
* Setting stdin to binary by default causes
* Ctrl-C to not raise SIGINT. We must undo
* that side-effect.
*/
__djgpp_set_ctrl_c(1);
#endif
} else if (strcmp(open_filename, FAKE_EMPTYFILE) == 0)
{
f = -1;
chflags |= CH_NODATA;
} else if (strcmp(open_filename, FAKE_HELPFILE) == 0)
{
f = -1;
chflags |= CH_HELPFILE;
} else if ((parg.p_string = bad_file(open_filename)) != NULL)
{
/*
* It looks like a bad file. Don't try to open it.
*/
error("%s", &parg);
free(parg.p_string);
return edit_error(filename, alt_filename, altpipe, ifile, was_curr_ifile);
} else if ((f = open(open_filename, OPEN_READ)) < 0)
{
/*
* Got an error trying to open it.
*/
parg.p_string = errno_message(filename);
error("%s", &parg);
free(parg.p_string);
return edit_error(filename, alt_filename, altpipe, ifile, was_curr_ifile);
} else
{
chflags |= CH_CANSEEK;
if (!force_open && !opened(ifile) && bin_file(f))
{
/*
* Looks like a binary file.
* Ask user if we should proceed.
*/
parg.p_string = filename;
answer = query("\"%s\" may be a binary file. See it anyway? ",
&parg);
if (answer != 'y' && answer != 'Y')
{
close(f);
return edit_error(filename, alt_filename, altpipe, ifile, was_curr_ifile);
}
}
}
}
if (!force_open && f >= 0 && isatty(f))
{
PARG parg;
parg.p_string = filename;
error("%s is a terminal (use -f to open it)", &parg);
return edit_error(filename, alt_filename, altpipe, ifile, was_curr_ifile);
}
/*
* Get the new ifile.
* Get the saved position for the file.
*/
if (was_curr_ifile != NULL_IFILE)
{
old_ifile = was_curr_ifile;
unsave_ifile(was_curr_ifile);
}
curr_ifile = ifile;
set_altfilename(curr_ifile, alt_filename);
set_altpipe(curr_ifile, altpipe);
set_open(curr_ifile); /* File has been opened */
get_pos(curr_ifile, &initial_scrpos);
new_file = TRUE;
ch_init(f, chflags);
consecutive_nulls = 0;
check_modelines();
if (!(chflags & CH_HELPFILE))
{
#if LOGFILE
if (namelogfile != NULL && is_tty)
use_logfile(namelogfile);
#endif
#if HAVE_STAT_INO
/* Remember the i-number and device of the opened file. */
if (strcmp(open_filename, "-") != 0)
{
struct stat statbuf;
int r = stat(open_filename, &statbuf);
if (r == 0)
{
curr_ino = statbuf.st_ino;
curr_dev = statbuf.st_dev;
}
}
#endif
if (every_first_cmd != NULL)
{
ungetsc(every_first_cmd);
ungetcc_back(CHAR_END_COMMAND);
}
}
/*
* Edit a space-separated list of files.
* For each filename in the list, enter it into the ifile list.
* Then edit the first one.
*/
public int edit_list(char *filelist)
{
IFILE save_ifile;
char *good_filename;
char *filename;
char *gfilelist;
char *gfilename;
char *qfilename;
struct textlist tl_files;
struct textlist tl_gfiles;
/*
* Run thru each filename in the list.
* Try to glob the filename.
* If it doesn't expand, just try to open the filename.
* If it does expand, try to open each name in that list.
*/
init_textlist(&tl_files, filelist);
filename = NULL;
while ((filename = forw_textlist(&tl_files, filename)) != NULL)
{
gfilelist = lglob(filename);
init_textlist(&tl_gfiles, gfilelist);
gfilename = NULL;
while ((gfilename = forw_textlist(&tl_gfiles, gfilename)) != NULL)
{
qfilename = shell_unquote(gfilename);
if (edit(qfilename) == 0 && good_filename == NULL)
good_filename = get_filename(curr_ifile);
free(qfilename);
}
free(gfilelist);
}
/*
* Edit the first valid filename in the list.
*/
if (good_filename == NULL)
{
unsave_ifile(save_ifile);
return (1);
}
if (get_ifile(good_filename, curr_ifile) == curr_ifile)
{
/*
* Trying to edit the current file; don't reopen it.
*/
unsave_ifile(save_ifile);
return (0);
}
reedit_ifile(save_ifile);
return (edit(good_filename));
}
/*
* Edit the first file in the command line (ifile) list.
*/
public int edit_first(void)
{
if (nifile() == 0)
return (edit_stdin());
curr_ifile = NULL_IFILE;
return (edit_next(1));
}
/*
* Edit the last file in the command line (ifile) list.
*/
public int edit_last(void)
{
curr_ifile = NULL_IFILE;
return (edit_prev(1));
}
/*
* Edit the n-th next or previous file in the command line (ifile) list.
*/
static int edit_istep(IFILE h, int n, int dir)
{
IFILE next;
/*
* Skip n filenames, then try to edit each filename.
*/
for (;;)
{
next = (dir > 0) ? next_ifile(h) : prev_ifile(h);
if (--n < 0)
{
if (edit_ifile(h) == 0)
break;
}
if (next == NULL_IFILE)
{
/*
* Reached end of the ifile list.
*/
return (1);
}
if (ABORT_SIGS())
{
/*
* Interrupt breaks out, if we're in a long
* list of files that can't be opened.
*/
return (1);
}
h = next;
}
/*
* Found a file that we can edit.
*/
return (0);
}
static int edit_inext(IFILE h, int n)
{
return (edit_istep(h, n, +1));
}
public int edit_next(int n)
{
return edit_istep(curr_ifile, n, +1);
}
static int edit_iprev(IFILE h, int n)
{
return (edit_istep(h, n, -1));
}
public int edit_prev(int n)
{
return edit_istep(curr_ifile, n, -1);
}
/*
* Edit a specific file in the command line (ifile) list.
*/
public int edit_index(int n)
{
IFILE h;
h = NULL_IFILE;
do
{
if ((h = next_ifile(h)) == NULL_IFILE)
{
/*
* Reached end of the list without finding it.
*/
return (1);
}
} while (get_index(h) != n);
return (edit_ifile(h));
}
public IFILE save_curr_ifile(void)
{
if (curr_ifile != NULL_IFILE)
hold_ifile(curr_ifile, 1);
return (curr_ifile);
}
public void unsave_ifile(IFILE save_ifile)
{
if (save_ifile != NULL_IFILE)
hold_ifile(save_ifile, -1);
}
/*
* Reedit the ifile which was previously open.
*/
public void reedit_ifile(IFILE save_ifile)
{
IFILE next;
IFILE prev;
/*
* Try to reopen the ifile.
* Note that opening it may fail (maybe the file was removed),
* in which case the ifile will be deleted from the list.
* So save the next and prev ifiles first.
*/
unsave_ifile(save_ifile);
next = next_ifile(save_ifile);
prev = prev_ifile(save_ifile);
if (edit_ifile(save_ifile) == 0)
return;
/*
* If can't reopen it, open the next input file in the list.
*/
if (next != NULL_IFILE && edit_inext(next, 0) == 0)
return;
/*
* If can't open THAT one, open the previous input file in the list.
*/
if (prev != NULL_IFILE && edit_iprev(prev, 0) == 0)
return;
/*
* If can't even open that, we're stuck. Just quit.
*/
quit(QUIT_ERROR);
}
/*
* Edit standard input.
*/
public int edit_stdin(void)
{
if (isatty(fd0))
{
error("Missing filename (\"less --help\" for help)", NULL_PARG);
quit(QUIT_OK);
}
return (edit("-"));
}
/*
* Copy a file directly to standard output.
* Used if standard output is not a tty.
*/
public void cat_file(void)
{
int c;
while ((c = ch_forw_get()) != EOI)
putchr(c);
flush();
}
#if LOGFILE
#define OVERWRITE_OPTIONS "Overwrite, Append, Don't log, or Quit?"
/*
* If the user asked for a log file and our input file
* is standard input, create the log file.
* We take care not to blindly overwrite an existing file.
*/
public void use_logfile(char *filename)
{
int exists;
int answer;
PARG parg;
if (ch_getflags() & CH_CANSEEK)
/*
* Can't currently use a log file on a file that can seek.
*/
return;
/*
* {{ We could use access() here. }}
*/
exists = open(filename, OPEN_READ);
if (exists >= 0)
close(exists);
exists = (exists >= 0);
/*
* Decide whether to overwrite the log file or append to it.
* If it doesn't exist we "overwrite" it.
*/
if (!exists || force_logfile)
{
/*
* Overwrite (or create) the log file.
*/
answer = 'O';
} else
{
/*
* Ask user what to do.
*/
parg.p_string = filename;
answer = query("Warning: \"%s\" exists; "OVERWRITE_OPTIONS" ", &parg);
}
loop:
switch (answer)
{
case 'O': case 'o':
/*
* Overwrite: create the file.
*/
logfile = creat(filename, CREAT_RW);
break;
case 'A': case 'a':
/*
* Append: open the file and seek to the end.
*/
logfile = open(filename, OPEN_APPEND);
if (lseek(logfile, (off_t)0, SEEK_END) == BAD_LSEEK)
{
close(logfile);
logfile = -1;
}
break;
case 'D': case 'd':
/*
* Don't do anything.
*/
return;
default:
/*
* Eh?
*/
