/*
* 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.
*/
/*
* Routines to mess around with filenames (and files).
* Much of this is very OS dependent.
*/
extern int force_open;
extern int secure;
extern int use_lessopen;
extern int ctldisp;
extern int utf_mode;
extern IFILE curr_ifile;
extern IFILE old_ifile;
#if SPACES_IN_FILENAMES
extern char openquote;
extern char closequote;
#endif
#if HAVE_STAT_INO
extern ino_t curr_ino;
extern dev_t curr_dev;
#endif
/*
* Remove quotes around a filename.
*/
public char * shell_unquote(char *str)
{
char *name;
char *p;
name = p = (char *) ecalloc(strlen(str)+1, sizeof(char));
if (*str == openquote)
{
str++;
while (*str != '\0')
{
if (*str == closequote)
{
if (str[1] != closequote)
break;
str++;
}
*p++ = *str++;
}
} else
{
char *esc = get_meta_escape();
int esclen = (int) strlen(esc);
while (*str != '\0')
{
if (esclen > 0 && strncmp(str, esc, esclen) == 0)
str += esclen;
*p++ = *str++;
}
}
*p = '\0';
return (name);
}
/*
* Get the shell's escape character.
*/
public char * get_meta_escape(void)
{
char *s;
s = lgetenv("LESSMETAESCAPE");
if (s == NULL)
s = DEF_METAESCAPE;
return (s);
}
/*
* Get the characters which the shell considers to be "metacharacters".
*/
static char * metachars(void)
{
static char *mchars = NULL;
if (mchars == NULL)
{
mchars = lgetenv("LESSMETACHARS");
if (mchars == NULL)
mchars = DEF_METACHARS;
}
return (mchars);
}
/*
* Is this a shell metacharacter?
*/
static int metachar(char c)
{
return (strchr(metachars(), c) != NULL);
}
/*
* Insert a backslash before each metacharacter in a string.
*/
public char * shell_quote(char *s)
{
char *p;
char *newstr;
int len;
char *esc = get_meta_escape();
int esclen = (int) strlen(esc);
int use_quotes = 0;
int have_quotes = 0;
/*
* Determine how big a string we need to allocate.
*/
len = 1; /* Trailing null byte */
for (p = s; *p != '\0'; p++)
{
len++;
if (*p == openquote || *p == closequote)
have_quotes = 1;
if (metachar(*p))
{
if (esclen == 0)
{
/*
* We've got a metachar, but this shell
* doesn't support escape chars. Use quotes.
*/
use_quotes = 1;
} else
{
/*
* Allow space for the escape char.
*/
len += esclen;
}
}
}
if (use_quotes)
{
if (have_quotes)
/*
* We can't quote a string that contains quotes.
*/
return (NULL);
len = (int) strlen(s) + 3;
}
/*
* Allocate and construct the new string.
*/
newstr = p = (char *) ecalloc(len, sizeof(char));
if (use_quotes)
{
SNPRINTF3(newstr, len, "%c%s%c", openquote, s, closequote);
} else
{
while (*s != '\0')
{
if (metachar(*s))
{
/*
* Add the escape char.
*/
strcpy(p, esc);
p += esclen;
}
*p++ = *s++;
}
*p = '\0';
}
return (newstr);
}
/*
* Return a pathname that points to a specified file in a specified directory.
* Return NULL if the file does not exist in the directory.
*/
public char * dirfile(char *dirname, char *filename, int must_exist)
{
char *pathname;
int len;
int f;
if (dirname == NULL || *dirname == '\0')
return (NULL);
/*
* Construct the full pathname.
*/
len = (int) (strlen(dirname) + strlen(filename) + 2);
pathname = (char *) calloc(len, sizeof(char));
if (pathname == NULL)
return (NULL);
SNPRINTF3(pathname, len, "%s%s%s", dirname, PATHNAME_SEP, filename);
if (must_exist)
{
/*
* Make sure the file exists.
*/
f = open(pathname, OPEN_READ);
if (f < 0)
{
free(pathname);
pathname = NULL;
} else
{
close(f);
}
}
return (pathname);
}
/*
* Return the full pathname of the given file in the "home directory".
*/
public char * homefile(char *filename)
{
char *pathname;
/*
* Expand a string, substituting any "%" with the current filename,
* and any "#" with the previous filename.
* But a string of N "%"s is just replaced with N-1 "%"s.
* Likewise for a string of N "#"s.
* {{ This is a lot of work just to support % and #. }}
*/
public char * fexpand(char *s)
{
char *fr, *to;
int n;
char *e;
IFILE ifile;
/*
* Make one pass to see how big a buffer we
* need to allocate for the expanded string.
*/
n = 0;
for (fr = s; *fr != '\0'; fr++)
{
switch (*fr)
{
case '%':
case '#':
if (fr > s && fr[-1] == *fr)
{
/*
* Second (or later) char in a string
* of identical chars. Treat as normal.
*/
n++;
} else if (fr[1] != *fr)
{
/*
* Single char (not repeated). Treat specially.
*/
ifile = fchar_ifile(*fr);
if (ifile == NULL_IFILE)
n++;
else
n += (int) strlen(get_filename(ifile));
}
/*
* Else it is the first char in a string of
* identical chars. Just discard it.
*/
break;
default:
n++;
break;
}
}
e = (char *) ecalloc(n+1, sizeof(char));
/*
* Now copy the string, expanding any "%" or "#".
*/
to = e;
for (fr = s; *fr != '\0'; fr++)
{
switch (*fr)
{
case '%':
case '#':
if (fr > s && fr[-1] == *fr)
{
*to++ = *fr;
} else if (fr[1] != *fr)
{
ifile = fchar_ifile(*fr);
if (ifile == NULL_IFILE)
*to++ = *fr;
else
{
strcpy(to, get_filename(ifile));
to += strlen(to);
}
}
break;
default:
*to++ = *fr;
break;
}
}
*to = '\0';
return (e);
}
#if TAB_COMPLETE_FILENAME
/*
* Return a blank-separated list of filenames which "complete"
* the given string.
*/
public char * fcomplete(char *s)
{
char *fpat;
char *qs;
if (secure)
return (NULL);
/*
* Complete the filename "s" by globbing "s*".
*/
#if MSDOS_COMPILER && (MSDOS_COMPILER == MSOFTC || MSDOS_COMPILER == BORLANDC)
/*
* But in DOS, we have to glob "s*.*".
* But if the final component of the filename already has
* a dot in it, just do "s*".
* (Thus, "FILE" is globbed as "FILE*.*",
* but "FILE.A" is globbed as "FILE.A*").
*/
{
char *slash;
int len;
for (slash = s+strlen(s)-1; slash > s; slash--)
if (*slash == *PATHNAME_SEP || *slash == '/')
break;
len = (int) strlen(s) + 4;
fpat = (char *) ecalloc(len, sizeof(char));
if (strchr(slash, '.') == NULL)
SNPRINTF1(fpat, len, "%s*.*", s);
else
SNPRINTF1(fpat, len, "%s*", s);
}
#else
{
int len = (int) strlen(s) + 2;
fpat = (char *) ecalloc(len, sizeof(char));
SNPRINTF1(fpat, len, "%s*", s);
}
#endif
qs = lglob(fpat);
s = shell_unquote(qs);
if (strcmp(s,fpat) == 0)
{
/*
* The filename didn't expand.
*/
free(qs);
qs = NULL;
}
free(s);
free(fpat);
return (qs);
}
#endif
/*
* Try to determine if a file is "binary".
* This is just a guess, and we need not try too hard to make it accurate.
*/
public int bin_file(int f)
{
int n;
int bin_count = 0;
char data[256];
char* p;
char* edata;
if (!seekable(f))
return (0);
if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
return (0);
n = read(f, data, sizeof(data));
if (n <= 0)
return (0);
edata = &data[n];
for (p = data; p < edata; )
{
if (utf_mode && !is_utf8_well_formed(p, edata-p))
{
bin_count++;
utf_skip_to_lead(&p, edata);
} else
{
LWCHAR c = step_char(&p, +1, edata);
struct ansi_state *pansi;
if (ctldisp == OPT_ONPLUS && (pansi = ansi_start(c)) != NULL)
{
skip_ansi(pansi, &p, edata);
ansi_done(pansi);
} else if (binary_char(c))
bin_count++;
}
}
/*
* Call it a binary file if there are more than 5 binary characters
* in the first 256 bytes of the file.
*/
return (bin_count > 5);
}
/*
* Try to determine the size of a file by seeking to the end.
*/
static POSITION seek_filesize(int f)
{
off_t spos;
#if HAVE_POPEN
/*
* Read a string from a file.
* Return a pointer to the string in memory.
*/
static char * readfd(FILE *fd)
{
int len;
int ch;
char *buf;
char *p;
/*
* Make a guess about how many chars in the string
* and allocate a buffer to hold it.
*/
len = 100;
buf = (char *) ecalloc(len, sizeof(char));
for (p = buf; ; p++)
{
if ((ch = getc(fd)) == '\n' || ch == EOF)
break;
if (p - buf >= len-1)
{
/*
* The string is too big to fit in the buffer we have.
* Allocate a new buffer, twice as big.
*/
len *= 2;
*p = '\0';
p = (char *) ecalloc(len, sizeof(char));
strcpy(p, buf);
free(buf);
buf = p;
p = buf + strlen(buf);
}
*p = ch;
}
*p = '\0';
return (buf);
}
/*
* Execute a shell command.
* Return a pointer to a pipe connected to the shell command's standard output.
*/
static FILE * shellcmd(char *cmd)
{
FILE *fd;
#if HAVE_SHELL
char *shell;
shell = lgetenv("SHELL");
if (!isnullenv(shell))
{
char *scmd;
char *esccmd;
/*
* Read the output of <$SHELL -c cmd>.
* Escape any metacharacters in the command.
*/
esccmd = shell_quote(cmd);
if (esccmd == NULL)
{
fd = popen(cmd, "r");
} else
{
int len = (int) (strlen(shell) + strlen(esccmd) + 5);
scmd = (char *) ecalloc(len, sizeof(char));
SNPRINTF3(scmd, len, "%s %s %s", shell, shell_coption(), esccmd);
free(esccmd);
fd = popen(scmd, "r");
free(scmd);
}
} else
#endif
{
fd = popen(cmd, "r");
}
/*
* Redirection in `popen' might have messed with the
* standard devices. Restore binary input mode.
*/
SET_BINARY(0);
return (fd);
}
#endif /* HAVE_POPEN */
/*
* Expand a filename, doing any system-specific metacharacter substitutions.
*/
public char * lglob(char *filename)
{
char *gfilename;
filename = fexpand(filename);
if (secure)
return (filename);
#ifdef DECL_GLOB_LIST
{
/*
* The globbing function returns a list of names.
*/
int length;
char *p;
char *qfilename;
DECL_GLOB_LIST(list)
GLOB_LIST(filename, list);
if (GLOB_LIST_FAILED(list))
{
return (filename);
}
length = 1; /* Room for trailing null byte */
for (SCAN_GLOB_LIST(list, p))
{
INIT_GLOB_LIST(list, p);
qfilename = shell_quote(p);
if (qfilename != NULL)
{
length += strlen(qfilename) + 1;
free(qfilename);
}
}
gfilename = (char *) ecalloc(length, sizeof(char));
for (SCAN_GLOB_LIST(list, p))
{
INIT_GLOB_LIST(list, p);
qfilename = shell_quote(p);
if (qfilename != NULL)
{
sprintf(gfilename + strlen(gfilename), "%s ", qfilename);
free(qfilename);
}
}
/*
* Overwrite the final trailing space with a null terminator.
*/
*--p = '\0';
GLOB_LIST_DONE(list);
}
#else
#ifdef DECL_GLOB_NAME
{
/*
* The globbing function returns a single name, and
* is called multiple times to walk thru all names.
*/
char *p;
int len;
int n;
char *pfilename;
char *qfilename;
DECL_GLOB_NAME(fnd,drive,dir,fname,ext,handle)
GLOB_FIRST_NAME(filename, &fnd, handle);
if (GLOB_FIRST_FAILED(handle))
{
return (filename);
}
_splitpath(filename, drive, dir, fname, ext);
len = 100;
gfilename = (char *) ecalloc(len, sizeof(char));
p = gfilename;
do {
n = (int) (strlen(drive) + strlen(dir) + strlen(fnd.GLOB_NAME) + 1);
pfilename = (char *) ecalloc(n, sizeof(char));
SNPRINTF3(pfilename, n, "%s%s%s", drive, dir, fnd.GLOB_NAME);
qfilename = shell_quote(pfilename);
free(pfilename);
if (qfilename != NULL)
{
n = (int) strlen(qfilename);
while (p - gfilename + n + 2 >= len)
{
/*
* No room in current buffer.
* Allocate a bigger one.
*/
len *= 2;
*p = '\0';
p = (char *) ecalloc(len, sizeof(char));
strcpy(p, gfilename);
free(gfilename);
gfilename = p;
p = gfilename + strlen(gfilename);
}
strcpy(p, qfilename);
free(qfilename);
p += n;
*p++ = ' ';
}
} while (GLOB_NEXT_NAME(handle, &fnd) == 0);
/*
* Overwrite the final trailing space with a null terminator.
*/
*--p = '\0';
GLOB_NAME_DONE(handle);
}
#else
#if HAVE_POPEN
{
/*
* We get the shell to glob the filename for us by passing
* an "echo" command to the shell and reading its output.
*/
FILE *fd;
char *s;
char *lessecho;
char *cmd;
char *esc;
int len;
esc = get_meta_escape();
if (strlen(esc) == 0)
esc = "-";
esc = shell_quote(esc);
if (esc == NULL)
{
return (filename);
}
lessecho = lgetenv("LESSECHO");
if (isnullenv(lessecho))
lessecho = "lessecho";
/*
* Invoke lessecho, and read its output (a globbed list of filenames).
*/
len = (int) (strlen(lessecho) + strlen(filename) + (7*strlen(metachars())) + 24);
cmd = (char *) ecalloc(len, sizeof(char));
SNPRINTF4(cmd, len, "%s -p0x%x -d0x%x -e%s ", lessecho,
(unsigned char) openquote, (unsigned char) closequote, esc);
free(esc);
for (s = metachars(); *s != '\0'; s++)
sprintf(cmd + strlen(cmd), "-n0x%x ", (unsigned char) *s);
sprintf(cmd + strlen(cmd), "-- %s", filename);
fd = shellcmd(cmd);
free(cmd);
if (fd == NULL)
{
/*
* Cannot create the pipe.
* Just return the original (fexpanded) filename.
*/
return (filename);
}
gfilename = readfd(fd);
pclose(fd);
if (*gfilename == '\0')
{
free(gfilename);
return (filename);
}
}
#else
/*
* No globbing functions at all. Just use the fexpanded filename.
*/
gfilename = save(filename);
#endif
#endif
#endif
free(filename);
return (gfilename);
}
/*
* Does path not represent something in the file system?
*/
public int is_fake_pathname(char *path)
{
return (strcmp(path, "-") == 0 ||
strcmp(path, FAKE_HELPFILE) == 0 || strcmp(path, FAKE_EMPTYFILE) == 0);
}
#if HAVE_POPEN
/*
* Return number of %s escapes in a string.
* Return a large number if there are any other % escapes besides %s.
*/
static int num_pct_s(char *lessopen)
{
int num = 0;
while (*lessopen != '\0')
{
if (*lessopen == '%')
{
if (lessopen[1] == '%')
++lessopen;
else if (lessopen[1] == 's')
++num;
else
return (999);
}
++lessopen;
}
return (num);
}
#endif
/*
* See if we should open a "replacement file"
* instead of the file we're about to open.
*/
public char * open_altfile(char *filename, int *pf, void **pfd)
{
#if !HAVE_POPEN
return (NULL);
#else
char *lessopen;
char *qfilename;
char *cmd;
int len;
FILE *fd;
#if HAVE_FILENO
int returnfd = 0;
#endif
if (!use_lessopen || secure)
return (NULL);
ch_ungetchar(-1);
if ((lessopen = lgetenv("LESSOPEN")) == NULL)
return (NULL);
while (*lessopen == '|')
{
/*
* If LESSOPEN starts with a |, it indicates
* a "pipe preprocessor".
*/
#if !HAVE_FILENO
error("LESSOPEN pipe is not supported", NULL_PARG);
return (NULL);
#else
lessopen++;
returnfd++;
#endif
}
if (*lessopen == '-')
{
/*
* Lessopen preprocessor will accept "-" as a filename.
*/
lessopen++;
} else
{
if (strcmp(filename, "-") == 0)
return (NULL);
}
if (num_pct_s(lessopen) != 1)
{
error("LESSOPEN ignored: must contain exactly one %%s", NULL_PARG);
return (NULL);
}
qfilename = shell_quote(filename);
len = (int) (strlen(lessopen) + strlen(qfilename) + 2);
cmd = (char *) ecalloc(len, sizeof(char));
SNPRINTF1(cmd, len, lessopen, qfilename);
free(qfilename);
fd = shellcmd(cmd);
free(cmd);
if (fd == NULL)
{
/*
* Cannot create the pipe.
*/
return (NULL);
}
#if HAVE_FILENO
if (returnfd)
{
char c;
int f;
/*
* The alt file is a pipe. Read one char
* to see if the pipe will produce any data.
* If it does, push the char back on the pipe.
*/
f = fileno(fd);
SET_BINARY(f);
if (read(f, &c, 1) != 1)
{
/*
* Pipe is empty.
* If more than 1 pipe char was specified,
* the exit status tells whether the file itself
* is empty, or if there is no alt file.
* If only one pipe char, just assume no alt file.
*/
int status = pclose(fd);
if (returnfd > 1 && status == 0) {
/* File is empty. */
*pfd = NULL;
*pf = -1;
return (save(FAKE_EMPTYFILE));
}
/* No alt file. */
return (NULL);
}
/* Alt pipe contains data, so use it. */
ch_ungetchar(c);
*pfd = (void *) fd;
*pf = f;
return (save("-"));
}
#endif
/* The alt file is a regular file. Read its name from LESSOPEN. */
cmd = readfd(fd);
pclose(fd);
if (*cmd == '\0')
{
/*
* Pipe is empty. This means there is no alt file.
*/
free(cmd);
return (NULL);
}
return (cmd);
#endif /* HAVE_POPEN */
}
/*
* Close a replacement file.
*/
public void close_altfile(char *altfilename, char *filename)
{
#if HAVE_POPEN
char *lessclose;
char *qfilename;
char *qaltfilename;
FILE *fd;
char *cmd;
int len;
if (secure)
return;
ch_ungetchar(-1);
if ((lessclose = lgetenv("LESSCLOSE")) == NULL)
return;
if (num_pct_s(lessclose) > 2)
{
error("LESSCLOSE ignored; must contain no more than 2 %%s", NULL_PARG);
return;
}
qfilename = shell_quote(filename);
qaltfilename = shell_quote(altfilename);
len = (int) (strlen(lessclose) + strlen(qfilename) + strlen(qaltfilename) + 2);
cmd = (char *) ecalloc(len, sizeof(char));
SNPRINTF2(cmd, len, lessclose, qfilename, qaltfilename);
free(qaltfilename);
free(qfilename);
fd = shellcmd(cmd);
free(cmd);
if (fd != NULL)
pclose(fd);
#endif
}
/*
* Is the specified file a directory?
*/
public int is_dir(char *filename)
{
int isdir = 0;
#if HAVE_STAT
{
int r;
struct stat statbuf;
r = stat(filename, &statbuf);
isdir = (r >= 0 && S_ISDIR(statbuf.st_mode));
}
#else
#ifdef _OSK
{
int f;
/*
* Returns NULL if the file can be opened and
* is an ordinary file, otherwise an error message
* (if it cannot be opened or is a directory, etc.)
*/
public char * bad_file(char *filename)
{
char *m = NULL;
if (!force_open && is_dir(filename))
{
static char is_a_dir[] = " is a directory";
m = (char *) ecalloc(strlen(filename) + sizeof(is_a_dir),
sizeof(char));
strcpy(m, filename);
strcat(m, is_a_dir);
} else
{
#if HAVE_STAT
int r;
struct stat statbuf;
r = stat(filename, &statbuf);
if (r < 0)
{
m = errno_message(filename);
} else if (force_open)
{
m = NULL;
} else if (!S_ISREG(statbuf.st_mode))
{
static char not_reg[] = " is not a regular file (use -f to see it)";
m = (char *) ecalloc(strlen(filename) + sizeof(not_reg),
sizeof(char));
strcpy(m, filename);
strcat(m, not_reg);
}
#endif
}
return (m);
}
/*
* Return the size of a file, as cheaply as possible.
* In Unix, we can stat the file.
*/
public POSITION filesize(int f)
{
#if HAVE_STAT
struct stat statbuf;
if (fstat(f, &statbuf) >= 0)
return ((POSITION) statbuf.st_size);
#else
#ifdef _OSK
long size;
public int curr_ifile_changed(void)
{
#if HAVE_STAT_INO
/*
* If the file's i-number or device has changed,
* or if the file is smaller than it previously was,
* the file must be different.
*/
struct stat st;
POSITION curr_pos = ch_tell();
int r = stat(get_filename(curr_ifile), &st);
if (r == 0 && (st.st_ino != curr_ino ||
st.st_dev != curr_dev ||
(curr_pos != NULL_POSITION && st.st_size < curr_pos)))
return (TRUE);
#endif
return (FALSE);
}
