busybox/coreutils/tr.c
2006-11-27 16:49:31 +00:00

254 lines
6.0 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.
*/
#include "busybox.h"
// Even with -funsigned-char, gcc still complains about char as an array index.
#define GCC4_IS_STUPID int
#define ASCII 0377
/* some "globals" shared across this file */
static char com_fl, del_fl, sq_fl;
/* these last are pointers to static buffers declared in tr_main */
static char *poutput, *pvector, *pinvec, *poutvec;
static void convert(void)
{
int read_chars = 0, in_index = 0, out_index = 0, c, coded, last = -1;
for (;;) {
// If we're out of input, flush output and read more input.
if (in_index == read_chars) {
if (out_index) {
if (write(1, (char *) poutput, out_index) != out_index)
bb_error_msg_and_die(bb_msg_write_error);
out_index = 0;
}
if ((read_chars = read(0, bb_common_bufsiz1, BUFSIZ)) <= 0) {
if (write(1, (char *) poutput, out_index) != out_index)
bb_error_msg(bb_msg_write_error);
exit(0);
}
in_index = 0;
}
c = bb_common_bufsiz1[in_index++];
coded = pvector[c];
if (del_fl && pinvec[c])
continue;
if (sq_fl && last == coded && (pinvec[c] || poutvec[coded]))
continue;
poutput[out_index++] = last = coded;
}
/* NOTREACHED */
}
static void map(char *string1, unsigned int string1_len,
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[(GCC4_IS_STUPID)string1[i]] = last;
else
pvector[(GCC4_IS_STUPID)string1[i]] = last = string2[j++];
}
}
/* supported constructs:
* Ranges, e.g., [0-9] ==> 0123456789
* Escapes, e.g., \a ==> Control-G
* Character classes, e.g. [:upper:] ==> A ... Z
*/
static unsigned int expand(const char *arg, char *buffer)
{
char *buffer_start = buffer;
int i, ac;
while (*arg) {
if (*arg == '\\') {
arg++;
*buffer++ = bb_process_escape_sequence(&arg);
} else if (*(arg+1) == '-') {
ac = *(arg+2);
if(ac == 0) {
*buffer++ = *arg++;
continue;
}
i = *arg;
while (i <= ac)
*buffer++ = i++;
arg += 3; /* Skip the assumed a-z */
} else if (*arg == '[') {
arg++;
i = *arg++;
if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
if (strncmp(arg, "alpha", 5) == 0) {
for (i = 'A'; i <= 'Z'; i++)
*buffer++ = i;
for (i = 'a'; i <= 'z'; i++)
*buffer++ = i;
}
else if (strncmp(arg, "alnum", 5) == 0) {
for (i = '0'; i <= '9'; i++)
*buffer++ = i;
for (i = 'A'; i <= 'Z'; i++)
*buffer++ = i;
for (i = 'a'; i <= 'z'; i++)
*buffer++ = i;
}
else if (strncmp(arg, "digit", 5) == 0)
for (i = '0'; i <= '9'; i++)
*buffer++ = i;
else if (strncmp(arg, "lower", 5) == 0)
for (i = 'a'; i <= 'z'; i++)
*buffer++ = i;
else if (strncmp(arg, "upper", 5) == 0)
for (i = 'A'; i <= 'Z'; i++)
*buffer++ = i;
else if (strncmp(arg, "space", 5) == 0) {
const char s[] = "\t\n\v\f\r ";
strcat((char*)buffer, s);
buffer += sizeof(s) - 1;
}
else if (strncmp(arg, "blank", 5) == 0) {
*buffer++ = '\t';
*buffer++ = ' ';
}
/* gcc gives a warning if braces aren't used here */
else if (strncmp(arg, "punct", 5) == 0) {
for (i = 0; i <= ASCII; i++)
if (isprint(i) && (!isalnum(i)) && (!isspace(i)))
*buffer++ = i;
}
else if (strncmp(arg, "cntrl", 5) == 0) {
for (i = 0; i <= ASCII; i++)
if (iscntrl(i))
*buffer++ = i;
}
else {
*buffer++ = '[';
*buffer++ = ':';
continue;
}
break;
}
if (ENABLE_FEATURE_TR_EQUIV && i == '=') {
*buffer++ = *arg;
/* skip the closing =] */
arg += 3;
continue;
}
if (*arg++ != '-') {
*buffer++ = '[';
arg -= 2;
continue;
}
ac = *arg++;
while (i <= ac)
*buffer++ = i++;
arg++; /* Skip the assumed ']' */
} else
*buffer++ = *arg++;
}
return (buffer - buffer_start);
}
static int complement(char *buffer, int buffer_len)
{
short 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)
{
unsigned char *ptr;
int output_length=0, input_length;
int idx = 1;
int i;
RESERVE_CONFIG_BUFFER(output, BUFSIZ);
RESERVE_CONFIG_BUFFER(vector, ASCII+1);
RESERVE_CONFIG_BUFFER(invec, ASCII+1);
RESERVE_CONFIG_BUFFER(outvec, ASCII+1);
/* ... but make them available globally */
poutput = output;
pvector = vector;
pinvec = invec;
poutvec = outvec;
if (argc > 1 && argv[idx][0] == '-') {
for (ptr = (unsigned char *) &argv[idx][1]; *ptr; ptr++) {
switch (*ptr) {
case 'c':
com_fl = TRUE;
break;
case 'd':
del_fl = TRUE;
break;
case 's':
sq_fl = TRUE;
break;
default:
bb_show_usage();
}
}
idx++;
}
for (i = 0; i <= ASCII; i++) {
vector[i] = i;
invec[i] = outvec[i] = FALSE;
}
if (argv[idx] != NULL) {
input_length = expand(argv[idx++], bb_common_bufsiz1);
if (com_fl)
input_length = complement(bb_common_bufsiz1, input_length);
if (argv[idx] != NULL) {
if (*argv[idx] == '\0')
bb_error_msg_and_die("STRING2 cannot be empty");
output_length = expand(argv[idx], output);
map(bb_common_bufsiz1, input_length, output, output_length);
}
for (i = 0; i < input_length; i++)
invec[(GCC4_IS_STUPID)bb_common_bufsiz1[i]] = TRUE;
for (i = 0; i < output_length; i++)
outvec[(GCC4_IS_STUPID)output[i]] = TRUE;
}
convert();
return 0;
}