hush/coreutils/tr.c
2008-07-05 09:18:54 +00:00

247 lines
6.4 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini tr implementation for busybox
*
** Copyright (c) 1987,1997, Prentice Hall All rights reserved.
*
* The name of Prentice Hall may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* Copyright (c) Michiel Huisjes
*
* This version of tr is adapted from Minix tr and was modified
* by Erik Andersen <andersen@codepoet.org> to be used in busybox.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* http://www.opengroup.org/onlinepubs/009695399/utilities/tr.html
* TODO: xdigit, graph, print
*/
#include "libbb.h"
#define ASCII 0377
static void map(char *pvector,
unsigned char *string1, unsigned int string1_len,
unsigned char *string2, unsigned int string2_len)
{
char last = '0';
unsigned int i, j;
for (j = 0, i = 0; i < string1_len; i++) {
if (string2_len <= j)
pvector[string1[i]] = last;
else
pvector[string1[i]] = last = string2[j++];
}
}
/* supported constructs:
* Ranges, e.g., 0-9 ==> 0123456789
* Ranges, e.g., [0-9] ==> 0123456789
* Escapes, e.g., \a ==> Control-G
* Character classes, e.g. [:upper:] ==> A...Z
* Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?)
*/
static unsigned int expand(const char *arg, char *buffer)
{
char *buffer_start = buffer;
unsigned i; /* can't be unsigned char: must be able to hold 256 */
unsigned char ac;
while (*arg) {
if (*arg == '\\') {
arg++;
*buffer++ = bb_process_escape_sequence(&arg);
continue;
}
if (arg[1] == '-') { /* "0-9..." */
ac = arg[2];
if (ac == '\0') { /* "0-": copy verbatim */
*buffer++ = *arg++; /* copy '0' */
continue; /* next iter will copy '-' and stop */
}
i = *arg;
while (i <= ac) /* ok: i is unsigned _int_ */
*buffer++ = i++;
arg += 3; /* skip 0-9 */
continue;
}
if (*arg == '[') { /* "[xyz..." */
arg++;
i = *arg++;
/* "[xyz...", i=x, arg points to y */
if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
#define CLO ":]\0"
static const char classes[] ALIGN1 =
"alpha"CLO "alnum"CLO "digit"CLO
"lower"CLO "upper"CLO "space"CLO
"blank"CLO "punct"CLO "cntrl"CLO;
#define CLASS_invalid 0 /* we increment the retval */
#define CLASS_alpha 1
#define CLASS_alnum 2
#define CLASS_digit 3
#define CLASS_lower 4
#define CLASS_upper 5
#define CLASS_space 6
#define CLASS_blank 7
#define CLASS_punct 8
#define CLASS_cntrl 9
//#define CLASS_xdigit 10
//#define CLASS_graph 11
//#define CLASS_print 12
smalluint j;
{ /* not really pretty.. */
char *tmp = xstrndup(arg, 7); // warning: xdigit would need 8, not 7
j = index_in_strings(classes, tmp) + 1;
free(tmp);
}
if (j == CLASS_alnum || j == CLASS_digit) {
for (i = '0'; i <= '9'; i++)
*buffer++ = i;
}
if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
for (i = 'A'; i <= 'Z'; i++)
*buffer++ = i;
}
if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
for (i = 'a'; i <= 'z'; i++)
*buffer++ = i;
}
if (j == CLASS_space || j == CLASS_blank) {
*buffer++ = '\t';
if (j == CLASS_space) {
*buffer++ = '\n';
*buffer++ = '\v';
*buffer++ = '\f';
*buffer++ = '\r';
}
*buffer++ = ' ';
}
if (j == CLASS_punct || j == CLASS_cntrl) {
for (i = '\0'; i <= ASCII; i++)
if ((j == CLASS_punct && isprint(i) && !isalnum(i) && !isspace(i))
|| (j == CLASS_cntrl && iscntrl(i)))
*buffer++ = i;
}
if (j == CLASS_invalid) {
*buffer++ = '[';
*buffer++ = ':';
continue;
}
break;
}
/* "[xyz...", i=x, arg points to y */
if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
*buffer++ = *arg; /* copy CHAR */
arg += 3; /* skip CHAR=] */
continue;
}
if (*arg != '-') { /* not [x-...] - copy verbatim */
*buffer++ = '[';
arg--; /* points to x */
continue; /* copy all, including eventual ']' */
}
/* [x-y...] */
arg++;
ac = *arg++;
while (i <= ac)
*buffer++ = i++;
arg++; /* skip the assumed ']' */
continue;
}
*buffer++ = *arg++;
}
return (buffer - buffer_start);
}
static int complement(char *buffer, int buffer_len)
{
int i, j, ix;
char conv[ASCII + 2];
ix = 0;
for (i = '\0'; i <= ASCII; i++) {
for (j = 0; j < buffer_len; j++)
if (buffer[j] == i)
break;
if (j == buffer_len)
conv[ix++] = i & ASCII;
}
memcpy(buffer, conv, ix);
return ix;
}
int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tr_main(int argc UNUSED_PARAM, char **argv)
{
int output_length = 0, input_length;
int i;
smalluint flags;
ssize_t read_chars = 0;
size_t in_index = 0, out_index = 0;
unsigned last = UCHAR_MAX + 1; /* not equal to any char */
unsigned char coded, c;
unsigned char *output = xmalloc(BUFSIZ);
char *vector = xzalloc((ASCII+1) * 3);
char *invec = vector + (ASCII+1);
char *outvec = vector + (ASCII+1) * 2;
#define TR_OPT_complement (1 << 0)
#define TR_OPT_delete (1 << 1)
#define TR_OPT_squeeze_reps (1 << 2)
flags = getopt32(argv, "+cds"); /* '+': stop at first non-option */
argv += optind;
for (i = 0; i <= ASCII; i++) {
vector[i] = i;
/*invec[i] = outvec[i] = FALSE; - done by xzalloc */
}
#define tr_buf bb_common_bufsiz1
if (*argv != NULL) {
input_length = expand(*argv++, tr_buf);
if (flags & TR_OPT_complement)
input_length = complement(tr_buf, input_length);
if (*argv) {
if (argv[0][0] == '\0')
bb_error_msg_and_die("STRING2 cannot be empty");
output_length = expand(*argv, (char *)output);
map(vector, (unsigned char *)tr_buf, input_length, output, output_length);
}
for (i = 0; i < input_length; i++)
invec[(unsigned char)tr_buf[i]] = TRUE;
for (i = 0; i < output_length; i++)
outvec[output[i]] = TRUE;
}
for (;;) {
/* If we're out of input, flush output and read more input. */
if ((ssize_t)in_index == read_chars) {
if (out_index) {
xwrite(STDOUT_FILENO, (char *)output, out_index);
out_index = 0;
}
read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
if (read_chars <= 0) {
if (read_chars < 0)
bb_perror_msg_and_die(bb_msg_read_error);
exit(EXIT_SUCCESS);
}
in_index = 0;
}
c = tr_buf[in_index++];
coded = vector[c];
if ((flags & TR_OPT_delete) && invec[c])
continue;
if ((flags & TR_OPT_squeeze_reps) && last == coded
&& (invec[c] || outvec[coded]))
continue;
output[out_index++] = last = coded;
}
/* NOTREACHED */
return EXIT_SUCCESS;
}