/* 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 source tree. */ /* http://www.opengroup.org/onlinepubs/009695399/utilities/tr.html * TODO: graph, print */ //kbuild:lib-$(CONFIG_TR) += tr.o //config:config TR //config: bool "tr" //config: default y //config: help //config: tr is used to squeeze, and/or delete characters from standard //config: input, writing to standard output. //config: //config:config FEATURE_TR_CLASSES //config: bool "Enable character classes (such as [:upper:])" //config: default y //config: depends on TR //config: help //config: Enable character classes, enabling commands such as: //config: tr [:upper:] [:lower:] to convert input into lowercase. //config: //config:config FEATURE_TR_EQUIV //config: bool "Enable equivalence classes" //config: default y //config: depends on TR //config: help //config: Enable equivalence classes, which essentially add the enclosed //config: character to the current set. For instance, tr [=a=] xyz would //config: replace all instances of 'a' with 'xyz'. This option is mainly //config: useful for cases when no other way of expressing a character //config: is possible. //usage:#define tr_trivial_usage //usage: "[-cds] STRING1 [STRING2]" //usage:#define tr_full_usage "\n\n" //usage: "Translate, squeeze, or delete characters from stdin, writing to stdout\n" //usage: "\n -c Take complement of STRING1" //usage: "\n -d Delete input characters coded STRING1" //usage: "\n -s Squeeze multiple output characters of STRING2 into one character" //usage: //usage:#define tr_example_usage //usage: "$ echo \"gdkkn vnqkc\" | tr [a-y] [b-z]\n" //usage: "hello world\n" #include "libbb.h" enum { ASCII = 256, /* string buffer needs to be at least as big as the whole "alphabet". * BUFSIZ == ASCII is ok, but we will realloc in expand * even for smallest patterns, let's avoid that by using *2: */ TR_BUFSIZ = (BUFSIZ > ASCII*2) ? BUFSIZ : ASCII*2, }; static void map(char *pvector, char *string1, unsigned string1_len, char *string2, unsigned string2_len) { char last = '0'; unsigned i, j; for (j = 0, i = 0; i < string1_len; i++) { if (string2_len <= j) pvector[(unsigned char)(string1[i])] = last; else pvector[(unsigned char)(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 * Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?) * not supported: * \ooo-\ooo - octal ranges * [x*N] - repeat char x N times * [x*] - repeat char x until it fills STRING2: * # echo qwe123 | /usr/bin/tr 123456789 '[d]' * qwe[d] * # echo qwe123 | /usr/bin/tr 123456789 '[d*]' * qweddd */ static unsigned expand(const char *arg, char **buffer_p) { char *buffer = *buffer_p; unsigned pos = 0; unsigned size = TR_BUFSIZ; unsigned i; /* can't be unsigned char: must be able to hold 256 */ unsigned char ac; while (*arg) { if (pos + ASCII > size) { size += ASCII; *buffer_p = buffer = xrealloc(buffer, size); } if (*arg == '\\') { arg++; buffer[pos++] = bb_process_escape_sequence(&arg); continue; } if (arg[1] == '-') { /* "0-9..." */ ac = arg[2]; if (ac == '\0') { /* "0-": copy verbatim */ buffer[pos++] = *arg++; /* copy '0' */ continue; /* next iter will copy '-' and stop */ } i = (unsigned char) *arg; while (i <= ac) /* ok: i is unsigned _int_ */ buffer[pos++] = i++; arg += 3; /* skip 0-9 */ continue; } if ((ENABLE_FEATURE_TR_CLASSES || ENABLE_FEATURE_TR_EQUIV) && *arg == '[' ) { arg++; i = (unsigned char) *arg++; /* "[xyz...". i=x, arg points to y */ if (ENABLE_FEATURE_TR_CLASSES && i == ':') { /* [:class:] */ #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 "xdigit"CLO; enum { CLASS_invalid = 0, /* we increment the retval */ CLASS_alpha = 1, CLASS_alnum = 2, CLASS_digit = 3, CLASS_lower = 4, CLASS_upper = 5, CLASS_space = 6, CLASS_blank = 7, CLASS_punct = 8, CLASS_cntrl = 9, CLASS_xdigit = 10, //CLASS_graph = 11, //CLASS_print = 12, }; smalluint j; char *tmp; /* xdigit needs 8, not 7 */ i = 7 + (arg[0] == 'x'); tmp = xstrndup(arg, i); j = index_in_strings(classes, tmp) + 1; free(tmp); if (j == CLASS_invalid) goto skip_bracket; arg += i; if (j == CLASS_alnum || j == CLASS_digit || j == CLASS_xdigit) { for (i = '0'; i <= '9'; i++) buffer[pos++] = i; } if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) { for (i = 'A'; i <= 'Z'; i++) buffer[pos++] = i; } if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) { for (i = 'a'; i <= 'z'; i++) buffer[pos++] = i; } if (j == CLASS_space || j == CLASS_blank) { buffer[pos++] = '\t'; if (j == CLASS_space) { buffer[pos++] = '\n'; buffer[pos++] = '\v'; buffer[pos++] = '\f'; buffer[pos++] = '\r'; } buffer[pos++] = ' '; } if (j == CLASS_punct || j == CLASS_cntrl) { for (i = '\0'; i < ASCII; i++) { if ((j == CLASS_punct && isprint_asciionly(i) && !isalnum(i) && !isspace(i)) || (j == CLASS_cntrl && iscntrl(i)) ) { buffer[pos++] = i; } } } if (j == CLASS_xdigit) { for (i = 'A'; i <= 'F'; i++) { buffer[pos + 6] = i | 0x20; buffer[pos++] = i; } pos += 6; } continue; } /* "[xyz...", i=x, arg points to y */ if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */ buffer[pos++] = *arg; /* copy CHAR */ if (!arg[0] || arg[1] != '=' || arg[2] != ']') bb_show_usage(); arg += 3; /* skip CHAR=] */ continue; } /* The rest of "[xyz..." cases is treated as normal * string, "[" has no special meaning here: * tr "[a-z]" "[A-Z]" can be written as tr "a-z" "A-Z", * also try tr "[a-z]" "_A-Z+" and you'll see that * [] is not special here. */ skip_bracket: arg -= 2; /* points to "[" in "[xyz..." */ } buffer[pos++] = *arg++; } return pos; } /* NB: buffer is guaranteed to be at least TR_BUFSIZE * (which is >= ASCII) big. */ static int complement(char *buffer, int buffer_len) { int len; char conv[ASCII]; unsigned char ch; len = 0; ch = '\0'; while (1) { if (memchr(buffer, ch, buffer_len) == NULL) conv[len++] = ch; if (++ch == '\0') break; } memcpy(buffer, conv, len); return len; } int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tr_main(int argc UNUSED_PARAM, char **argv) { int i; smalluint opts; ssize_t read_chars; size_t in_index, out_index; unsigned last = UCHAR_MAX + 1; /* not equal to any char */ unsigned char coded, c; char *str1 = xmalloc(TR_BUFSIZ); char *str2 = xmalloc(TR_BUFSIZ); int str2_length; int str1_length; char *vector = xzalloc(ASCII * 3); char *invec = vector + ASCII; char *outvec = vector + ASCII * 2; #define TR_OPT_complement (3 << 0) #define TR_OPT_delete (1 << 2) #define TR_OPT_squeeze_reps (1 << 3) for (i = 0; i < ASCII; i++) { vector[i] = i; /*invec[i] = outvec[i] = FALSE; - done by xzalloc */ } /* -C/-c difference is that -C complements "characters", * and -c complements "values" (binary bytes I guess). * In POSIX locale, these are the same. */ opt_complementary = "-1"; opts = getopt32(argv, "+Ccds"); /* '+': stop at first non-option */ argv += optind; str1_length = expand(*argv++, &str1); str2_length = 0; if (opts & TR_OPT_complement) str1_length = complement(str1, str1_length); if (*argv) { if (argv[0][0] == '\0') bb_error_msg_and_die("STRING2 cannot be empty"); str2_length = expand(*argv, &str2); map(vector, str1, str1_length, str2, str2_length); } for (i = 0; i < str1_length; i++) invec[(unsigned char)(str1[i])] = TRUE; for (i = 0; i < str2_length; i++) outvec[(unsigned char)(str2[i])] = TRUE; goto start_from; /* In this loop, str1 space is reused as input buffer, * str2 - as output one. */ 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, str2, out_index); start_from: out_index = 0; } read_chars = safe_read(STDIN_FILENO, str1, TR_BUFSIZ); if (read_chars <= 0) { if (read_chars < 0) bb_perror_msg_and_die(bb_msg_read_error); break; } in_index = 0; } c = str1[in_index++]; if ((opts & TR_OPT_delete) && invec[c]) continue; coded = vector[c]; if ((opts & TR_OPT_squeeze_reps) && last == coded && (invec[c] || outvec[coded]) ) { continue; } str2[out_index++] = last = coded; } if (ENABLE_FEATURE_CLEAN_UP) { free(vector); free(str2); free(str1); } return EXIT_SUCCESS; }