/* POSIX.2 wordexp implementation. Copyright (C) 1997, 1998 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Tim Waugh . The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Undefine the following line for the production version. */ /* #define NDEBUG 1 */ #include /* * This is a recursive-descent-style word expansion routine. */ /* These variables are defined and initialized in the startup code. */ extern int __libc_argc; extern char **__libc_argv; /* Some forward declarations */ static int parse_dollars (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white, int quoted) internal_function; static int parse_backtick (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) internal_function; static int parse_dquote (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) internal_function; static int eval_expr (char *expr, long int *result) internal_function; /* The w_*() functions manipulate word lists. */ #define W_CHUNK (100) static inline char * w_addchar (char *buffer, size_t *actlen, size_t *maxlen, char ch) /* (lengths exclude trailing zero) */ { /* Add a character to the buffer, allocating room for it if needed. */ if (*actlen == *maxlen) { char *old_buffer = buffer; assert (buffer == NULL || *maxlen != 0); *maxlen += W_CHUNK; buffer = realloc (buffer, 1 + *maxlen); if (buffer == NULL) free (old_buffer); } if (buffer != NULL) { buffer[*actlen] = ch; buffer[++(*actlen)] = '\0'; } return buffer; } static char * internal_function w_addmem (char *buffer, size_t *actlen, size_t *maxlen, const char *str, size_t len) { /* Add a string to the buffer, allocating room for it if needed. */ if (*actlen + len > *maxlen) { char *old_buffer = buffer; assert (buffer == NULL || *maxlen != 0); *maxlen += MAX (2 * len, W_CHUNK); buffer = realloc (old_buffer, 1 + *maxlen); if (buffer == NULL) free (old_buffer); } if (buffer != NULL) { *((char *) __mempcpy (&buffer[*actlen], str, len)) = '\0'; *actlen += len; } return buffer; } static char * internal_function w_addstr (char *buffer, size_t *actlen, size_t *maxlen, const char *str) /* (lengths exclude trailing zero) */ { /* Add a string to the buffer, allocating room for it if needed. */ size_t len; assert (str != NULL); /* w_addstr only called from this file */ len = strlen (str); return w_addmem (buffer, actlen, maxlen, str, len); } static int internal_function w_addword (wordexp_t *pwordexp, char *word) { /* Add a word to the wordlist */ size_t num_p; char **new_wordv; num_p = 2 + pwordexp->we_wordc + pwordexp->we_offs; new_wordv = realloc (pwordexp->we_wordv, sizeof (char *) * num_p); if (new_wordv != NULL) { pwordexp->we_wordv = new_wordv; pwordexp->we_wordv[pwordexp->we_wordc++] = word; pwordexp->we_wordv[pwordexp->we_wordc] = NULL; return 0; } return WRDE_NOSPACE; } /* The parse_*() functions should leave *offset being the offset in 'words' * to the last character processed. */ static int internal_function parse_backslash (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset) { /* We are poised _at_ a backslash, not in quotes */ switch (words[1 + *offset]) { case 0: /* Backslash is last character of input words */ return WRDE_SYNTAX; case '\n': ++(*offset); break; default: *word = w_addchar (*word, word_length, max_length, words[1 + *offset]); if (*word == NULL) return WRDE_NOSPACE; ++(*offset); break; } return 0; } static int internal_function parse_qtd_backslash (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset) { /* We are poised _at_ a backslash, inside quotes */ switch (words[1 + *offset]) { case 0: /* Backslash is last character of input words */ return WRDE_SYNTAX; case '\n': ++(*offset); break; case '$': case '`': case '"': case '\\': *word = w_addchar (*word, word_length, max_length, words[1 + *offset]); if (*word == NULL) return WRDE_NOSPACE; ++(*offset); break; default: *word = w_addchar (*word, word_length, max_length, words[*offset]); if (*word != NULL) *word = w_addchar (*word, word_length, max_length, words[1 + *offset]); if (*word == NULL) return WRDE_NOSPACE; ++(*offset); break; } return 0; } static int internal_function parse_tilde (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, size_t wordc) { /* We are poised _at_ a tilde */ size_t i; if (*word_length != 0) { if (!((*word)[*word_length - 1] == '=' && wordc == 0)) { if (!((*word)[*word_length - 1] == ':' && strchr (*word, '=') && wordc == 0)) { *word = w_addchar (*word, word_length, max_length, '~'); return *word ? 0 : WRDE_NOSPACE; } } } for (i = 1 + *offset; words[i]; i++) { if (words[i] == ':' || words[i] == '/' || words[i] == ' ' || words[i] == '\t' || words[i] == 0 ) break; if (words[i] == '\\') { *word = w_addchar (*word, word_length, max_length, '~'); return *word ? 0 : WRDE_NOSPACE; } } if (i == 1 + *offset) { /* Tilde appears on its own */ uid_t uid; struct passwd pwd, *tpwd; int buflen = 1000; char* buffer = __alloca (buflen); int result; uid = getuid (); while ((result = __getpwuid_r (uid, &pwd, buffer, buflen, &tpwd)) != 0 && errno == ERANGE) { buflen += 1000; buffer = __alloca (buflen); } if (result == 0 && pwd.pw_dir != NULL) { *word = w_addstr (*word, word_length, max_length, pwd.pw_dir); if (*word == NULL) return WRDE_NOSPACE; } else { *word = w_addchar (*word, word_length, max_length, '~'); if (*word == NULL) return WRDE_NOSPACE; } } else { /* Look up user name in database to get home directory */ char *user = __strndup (&words[1 + *offset], i - *offset); struct passwd pwd, *tpwd; int buflen = 1000; char* buffer = __alloca (buflen); int result; while ((result = __getpwnam_r (user, &pwd, buffer, buflen, &tpwd)) != 0 && errno == ERANGE) { buflen += 1000; buffer = __alloca (buflen); } if (result == 0 && pwd.pw_dir) *word = w_addstr (*word, word_length, max_length, pwd.pw_dir); else { /* (invalid login name) */ *word = w_addchar (*word, word_length, max_length, '~'); if (*word != NULL) *word = w_addstr (*word, word_length, max_length, user); } *offset = i - 1; } return *word ? 0 : WRDE_NOSPACE; } static int internal_function parse_glob (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) { /* We are poised just after a '*', a '[' or a '?'. */ int error; glob_t globbuf; int match; char *matching_word; int quoted = 0; /* 1 if singly-quoted, 2 if doubly */ for (; words[*offset]; (*offset)++) { if ((ifs && strchr (ifs, words[*offset])) || (!ifs && strchr (" \t\n", words[*offset]))) /* Reached IFS */ break; /* Sort out quoting */ if (words[*offset] == '\'') if (quoted == 0) { quoted = 1; continue; } else if (quoted == 1) { quoted = 0; continue; } else if (words[*offset] == '"') if (quoted == 0) { quoted = 2; continue; } else if (quoted == 2) { quoted = 0; continue; } /* Sort out other special characters */ if (quoted != 1 && words[*offset] == '$') { error = parse_dollars (word, word_length, max_length, words, offset, flags, pwordexp, ifs, ifs_white, quoted == 2); if (error) return error; continue; } else if (words[*offset] == '\\') { if (quoted) error = parse_qtd_backslash (word, word_length, max_length, words, offset); else error = parse_backslash (word, word_length, max_length, words, offset); if (error) return error; continue; } *word = w_addchar (*word, word_length, max_length, words[*offset]); if (*word == NULL) return WRDE_NOSPACE; } error = glob (*word, GLOB_NOCHECK, NULL, &globbuf); if (error != 0) { /* We can only run into memory problems. */ assert (error == GLOB_NOSPACE); return WRDE_NOSPACE; } if (ifs && !*ifs) { /* No field splitting allowed */ size_t length = strlen (globbuf.gl_pathv[0]); char *old_word = *word; *word = realloc (*word, length + 1); if (*word == NULL) { free (old_word); goto no_space; } memcpy (*word, globbuf.gl_pathv[0], length + 1); *word_length = length; for (match = 1; match < globbuf.gl_pathc && *word != NULL; ++match) { *word = w_addchar (*word, word_length, max_length, ' '); if (*word != NULL) *word = w_addstr (*word, word_length, max_length, globbuf.gl_pathv[match]); } /* Re-parse white space on return */ globfree (&globbuf); --(*offset); return *word ? 0 : WRDE_NOSPACE; } /* here ifs != "" */ free (*word); *word = NULL; *word_length = 0; matching_word = __strdup (globbuf.gl_pathv[0]); if (matching_word == NULL) goto no_space; if (w_addword (pwordexp, matching_word) == WRDE_NOSPACE) goto no_space; for (match = 1; match < globbuf.gl_pathc; ++match) { matching_word = __strdup (globbuf.gl_pathv[match]); if (matching_word == NULL) goto no_space; if (w_addword (pwordexp, matching_word) == WRDE_NOSPACE) goto no_space; } globfree (&globbuf); /* Re-parse white space on return */ --(*offset); return 0; no_space: globfree (&globbuf); return WRDE_NOSPACE; } static int internal_function parse_squote (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset) { /* We are poised just after a single quote */ for (; words[*offset]; ++(*offset)) { if (words[*offset] != '\'') { *word = w_addchar (*word, word_length, max_length, words[*offset]); if (*word == NULL) return WRDE_NOSPACE; } else return 0; } /* Unterminated string */ return WRDE_SYNTAX; } /* Functions to evaluate an arithmetic expression */ static int internal_function eval_expr_val (char **expr, long int *result) { int sgn = +1; char *digit; /* Skip white space */ for (digit = *expr; digit && *digit && isspace (*digit); ++digit); switch (*digit) { case '(': /* Scan for closing paren */ for (++digit; **expr && **expr != ')'; ++(*expr)); /* Is there one? */ if (!**expr) return WRDE_SYNTAX; *(*expr)++ = 0; if (eval_expr (digit, result)) return WRDE_SYNTAX; return 0; case '+': /* Positive value */ ++digit; break; case '-': /* Negative value */ ++digit; sgn = -1; break; default: if (!isdigit (*digit)) return WRDE_SYNTAX; } *result = 0; for (; *digit && isdigit (*digit); ++digit) *result = (*result * 10) + (*digit - '0'); *expr = digit; *result *= sgn; return 0; } static int internal_function eval_expr_multdiv (char **expr, long int *result) { long int arg; /* Read a Value */ if (eval_expr_val (expr, result) != 0) return WRDE_SYNTAX; while (**expr) { /* Skip white space */ for (; *expr && **expr && isspace (**expr); ++(*expr)); if (**expr == '*') { ++(*expr); if (eval_expr_val (expr, &arg) != 0) return WRDE_SYNTAX; *result *= arg; } else if (**expr == '/') { ++(*expr); if (eval_expr_val (expr, &arg) != 0) return WRDE_SYNTAX; *result /= arg; } else break; } return 0; } static int internal_function eval_expr (char *expr, long int *result) { long int arg; /* Read a Multdiv */ if (eval_expr_multdiv (&expr, result) != 0) return WRDE_SYNTAX; while (*expr) { /* Skip white space */ for (; expr && *expr && isspace (*expr); ++expr); if (*expr == '+') { ++expr; if (eval_expr_multdiv (&expr, &arg) != 0) return WRDE_SYNTAX; *result += arg; } else if (*expr == '-') { ++expr; if (eval_expr_multdiv (&expr, &arg) != 0) return WRDE_SYNTAX; *result -= arg; } else break; } return 0; } static int internal_function parse_arith (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, int bracket) { /* We are poised just after "$((" or "$[" */ int error; int paren_depth = 1; size_t expr_length = 0; size_t expr_maxlen = 0; char *expr = NULL; for (; words[*offset]; ++(*offset)) { switch (words[*offset]) { case '$': error = parse_dollars (&expr, &expr_length, &expr_maxlen, words, offset, flags, NULL, NULL, NULL, 1); /* The ``1'' here is to tell parse_dollars not to * split the fields. */ if (error) { free (expr); return error; } break; case '`': (*offset)++; error = parse_backtick (&expr, &expr_length, &expr_maxlen, words, offset, flags, NULL, NULL, NULL); /* The first NULL here is to tell parse_backtick not to * split the fields. */ if (error) { free (expr); return error; } break; case '\\': error = parse_qtd_backslash (&expr, &expr_length, &expr_maxlen, words, offset); if (error) { free (expr); return error; } /* I think that a backslash within an * arithmetic expansion is bound to * cause an error sooner or later anyway though. */ break; case ')': if (--paren_depth == 0) { char result[21]; /* 21 = ceil(log10(2^64)) + 1 */ long int numresult = 0; long long int convertme; if (bracket || words[1 + *offset] != ')') return WRDE_SYNTAX; ++(*offset); /* Go - evaluate. */ if (*expr && eval_expr (expr, &numresult) != 0) return WRDE_SYNTAX; if (numresult < 0) { convertme = -numresult; *word = w_addchar (*word, word_length, max_length, '-'); if (!*word) { free (expr); return WRDE_NOSPACE; } } else convertme = numresult; result[20] = '\0'; *word = w_addstr (*word, word_length, max_length, _itoa (convertme, &result[20], 10, 0)); free (expr); return *word ? 0 : WRDE_NOSPACE; } expr = w_addchar (expr, &expr_length, &expr_maxlen, words[*offset]); if (expr == NULL) return WRDE_NOSPACE; break; case ']': if (bracket && paren_depth == 1) { char result[21]; /* 21 = ceil(log10(2^64)) + 1 */ long int numresult = 0; /* Go - evaluate. */ if (*expr && eval_expr (expr, &numresult) != 0) return WRDE_SYNTAX; result[20] = '\0'; *word = w_addstr (*word, word_length, max_length, _itoa_word (numresult, &result[20], 10, 0)); free (expr); return *word ? 0 : WRDE_NOSPACE; } free (expr); return WRDE_SYNTAX; case '\n': case ';': case '{': case '}': free (expr); return WRDE_BADCHAR; case '(': ++paren_depth; default: expr = w_addchar (expr, &expr_length, &expr_maxlen, words[*offset]); if (expr == NULL) return WRDE_NOSPACE; } } /* Premature end */ free (expr); return WRDE_SYNTAX; } /* Function to execute a command and retrieve the results */ /* pwordexp contains NULL if field-splitting is forbidden */ static int internal_function exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) { int fildes[2]; int bufsize = 128; int buflen; int i; char *buffer; pid_t pid; /* Don't fork() unless necessary */ if (!comm || !*comm) return 0; if (pipe (fildes)) /* Bad */ return WRDE_NOSPACE; if ((pid = fork ()) < 0) { /* Bad */ return WRDE_NOSPACE; } if (pid == 0) { /* Child */ const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL }; /* Redirect output. */ dup2 (fildes[1], 1); close (fildes[1]); /* Redirect stderr to /dev/null if we have to. */ if ((flags & WRDE_SHOWERR) == 0) { int fd; close (2); fd = open (_PATH_DEVNULL, O_WRONLY); if (fd >= 0 && fd != 2) { dup2 (fd, 2); close (fd); } } close (fildes[0]); __execve (_PATH_BSHELL, (char *const *) args, __environ); /* Bad. What now? */ abort (); } /* Parent */ close (fildes[1]); buffer = __alloca (bufsize); if (!pwordexp) { /* Quoted - no field splitting */ while (1) { if ((buflen = read (fildes[0], buffer, bufsize)) < 1) { if (__waitpid (pid, NULL, WNOHANG) == 0) continue; if ((buflen = read (fildes[0], buffer, bufsize)) < 1) break; } *word = w_addmem (*word, word_length, max_length, buffer, buflen); if (*word == NULL) { kill (pid, SIGKILL); __waitpid (pid, NULL, 0); close (fildes[0]); return WRDE_NOSPACE; } } } else /* Not quoted - split fields */ { int copying = 0; /* 'copying' is: * 0 when searching for first character in a field not IFS white space * 1 when copying the text of a field * 2 when searching for possible non-whitespace IFS */ while (1) { if ((buflen = read (fildes[0], buffer, bufsize)) < 1) { if (__waitpid (pid, NULL, WNOHANG) == 0) continue; if ((read (fildes[0], buffer, bufsize)) < 1) break; } for (i = 0; i < buflen; ++i) { if (strchr (ifs, buffer[i]) != NULL) { /* Current character is IFS */ if (strchr (ifs_white, buffer[i]) == NULL) { /* Current character is IFS but not whitespace */ if (copying == 2) { /* current character * | * V * eg: textmoretext * * So, strip whitespace IFS (like at the start) */ copying = 0; continue; } copying = 0; /* fall through and delimit field.. */ } else { /* Current character is IFS white space */ /* If not copying a field, ignore it */ if (copying != 1) continue; /* End of field (search for non-IFS afterwards) */ copying = 2; } /* First IFS white space, or IFS non-whitespace. * Delimit the field. */ if (!*word) { /* This field is null, so make it an empty string */ *word = w_addchar (*word, word_length, max_length, 0); if (*word == NULL) { kill (pid, SIGKILL); __waitpid (pid, NULL, 0); close (fildes[0]); return WRDE_NOSPACE; } } if (w_addword (pwordexp, *word) == WRDE_NOSPACE) { kill (pid, SIGKILL); __waitpid (pid, NULL, 0); close (fildes[0]); return WRDE_NOSPACE; } *word = NULL; *word_length = 0; *max_length = 0; /* fall back round the loop.. */ } else { /* Not IFS character */ copying = 1; *word = w_addchar (*word, word_length, max_length, buffer[i]); if (*word == NULL) { kill (pid, SIGKILL); __waitpid (pid, NULL, 0); close (fildes[0]); return WRDE_NOSPACE; } } } } } /* Bash chops off trailing newlines, which seems sensible. */ while (*word_length > 0 && (*word)[*word_length - 1] == '\n') (*word)[--*word_length] = '\0'; close (fildes[0]); return 0; } static int internal_function parse_comm (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) { /* We are poised just after "$(" */ int paren_depth = 1; int error = 0; size_t comm_length = 0; size_t comm_maxlen = 0; char *comm = NULL; int quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */ for (; words[*offset]; ++(*offset)) { switch (words[*offset]) { case '\'': if (quoted == 0) quoted = 1; else if (quoted == 1) quoted = 0; break; case '"': if (quoted == 0) quoted = 2; else if (quoted == 2) quoted = 0; break; case ')': if (!quoted && --paren_depth == 0) { /* Go -- give script to the shell */ if (comm) { error = exec_comm (comm, word, word_length, max_length, flags, pwordexp, ifs, ifs_white); free (comm); } return error; } /* This is just part of the script */ break; case '(': if (!quoted) ++paren_depth; } comm = w_addchar (comm, &comm_length, &comm_maxlen, words[*offset]); if (comm == NULL) return WRDE_NOSPACE; } /* Premature end */ if (comm) free (comm); return WRDE_SYNTAX; } static int internal_function parse_param (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white, int quoted) { /* We are poised just after "$" */ enum action { ACT_NONE, ACT_RP_SHORT_LEFT = '#', ACT_RP_LONG_LEFT = 'L', ACT_RP_SHORT_RIGHT = '%', ACT_RP_LONG_RIGHT = 'R', ACT_NULL_ERROR = '?', ACT_NULL_SUBST = '-', ACT_NONNULL_SUBST = '+', ACT_NULL_ASSIGN = '=' }; size_t env_length = 0; size_t env_maxlen = 0; size_t pat_length = 0; size_t pat_maxlen = 0; size_t start = *offset; char *env = NULL; char *pattern = NULL; char *value = NULL; enum action action = ACT_NONE; int depth = 0; int colon_seen = 0; int seen_hash = 0; int free_value = 0; int pattern_is_quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */ int error; int brace = words[*offset] == '{'; if (brace) ++*offset; for (; words[*offset]; ++(*offset)) { int special; if (action != ACT_NONE) { switch (words[*offset]) { case '{': if (!pattern_is_quoted) ++depth; break; case '}': if (!pattern_is_quoted) { if (depth == 0) goto envsubst; --depth; } break; case '\\': if (!pattern_is_quoted && words[++*offset] == '\0') goto syntax; break; case '\'': if (pattern_is_quoted == 0) pattern_is_quoted = 1; else if (pattern_is_quoted == 1) pattern_is_quoted = 0; break; case '"': if (pattern_is_quoted == 0) pattern_is_quoted = 2; else if (pattern_is_quoted == 2) pattern_is_quoted = 0; break; } pattern = w_addchar (pattern, &pat_length, &pat_maxlen, words[*offset]); if (pattern == NULL) goto no_space; continue; } switch (words[*offset]) { case '}': if (!brace) goto end_of_word; if (env == NULL) goto syntax; /* Evaluate. */ goto envsubst; case '#': /* '#' only has special meaning inside braces or as the very * first character after $ */ if (*offset == start) { seen_hash = 1; goto envsubst; } if (!brace) /* Evaluate */ /* (and re-parse this character) */ goto end_of_word; /* At the start? (i.e. 'string length') */ if (env == NULL) { seen_hash = 1; continue; } else if (seen_hash) goto syntax; action = ACT_RP_SHORT_LEFT; if (words[1 + *offset] == '#') { ++*offset; action = ACT_RP_LONG_LEFT; } continue; case '%': if (!brace) /* Re-parse this character after substitution */ goto end_of_word; if (!env || !*env) goto syntax; if (seen_hash) goto syntax; action = ACT_RP_SHORT_RIGHT; if (words[1 + *offset] == '%') { ++*offset; action = ACT_RP_LONG_RIGHT; } continue; case ':': if (!brace) goto end_of_word; if (!env || !*env) goto syntax; if (seen_hash) goto syntax; if (words[1 + *offset] != '-' && words[1 + *offset] != '=' && words[1 + *offset] != '?' && words[1 + *offset] != '+') goto syntax; colon_seen = 1; action = words[++*offset]; continue; case '-': case '=': case '?': case '+': if (!brace) goto end_of_word; if (!env || !*env) goto syntax; action = words[*offset]; continue; } special = (strchr ("*@$", words[*offset]) != NULL || isdigit (words[*offset])); if (!isalpha (words[*offset]) && !special) /* Stop and evaluate, remembering char we stopped at */ break; env = w_addchar (env, &env_length, &env_maxlen, words[*offset]); if (env == NULL) goto no_space; if (special) { if (brace) ++*offset; goto envsubst; } } /* End of input string -- remember to reparse the character that we stopped * at. */ end_of_word: --(*offset); envsubst: if (words[start] == '{' && words[*offset] != '}') goto syntax; if (!env || !*env) { if (seen_hash) { /* $# expands to the number of positional parameters */ char buffer[21]; buffer[20] = '\0'; *word = w_addstr (*word, word_length, max_length, _itoa_word (__libc_argc - 1, &buffer[20], 10, 0)); } else { /* Just $ on its own */ *offset = start - 1; *word = w_addchar (*word, word_length, max_length, '$'); } if (env) free (env); return *word ? 0 : WRDE_NOSPACE; } /* Is it a special parameter? */ if (strpbrk (env, "0123456789*@$")) { if (env[1]) { /* Bad substitution if there is more than one character */ free (env); fprintf (stderr, "${%s}: bad substitution\n", env); return WRDE_SYNTAX; } /* Is it a digit? */ if (isdigit(*env)) { int n = *env - '0'; free (env); if (n >= __libc_argc) /* Substitute NULL */ return 0; /* Replace with the appropriate positional parameter */ value = __libc_argv[n]; goto maybe_fieldsplit; } /* Is it `$$' ? */ else if (*env == '$') { char pidstr[21]; free (env); pidstr[20] = '\0'; *word = w_addstr (*word, word_length, max_length, _itoa_word (getpid(), &pidstr[20], 10, 0)); return *word ? 0 : WRDE_NOSPACE; } /* Is it `$*' or `$@' (unquoted) ? */ else if (*env == '*' || (*env == '@' && !quoted)) { size_t plist_len = 1; int p; /* Build up value parameter by parameter (copy them) */ free (env); for (p = 1; __libc_argv[p]; ++p) { char *old_pointer = value; size_t argv_len = strlen (__libc_argv[p]); size_t old_plist_len = plist_len; if (value) value[plist_len - 1] = 0; plist_len += 1 + argv_len; /* First realloc will act as malloc because value is * initialised to NULL. */ value = realloc (value, plist_len); if (value == NULL) { free (old_pointer); return WRDE_NOSPACE; } memcpy (&value[old_plist_len - 1], __libc_argv[p], argv_len + 1); if (__libc_argv[p + 1]) { value[plist_len - 1] = '\0'; value[plist_len - 2] = ' '; } } free_value = 1; if (value) goto maybe_fieldsplit; return 0; } /* Must be a quoted `$@' */ assert (*env == '@'); assert (quoted); free (env); /* Each parameter is a separate word ("$@") */ if (__libc_argv[0] != NULL && __libc_argv[1] != NULL) { /* Append first parameter to current word. */ int p; *word = w_addstr (*word, word_length, max_length, __libc_argv[1]); if (*word == NULL) return WRDE_NOSPACE; for (p = 2; __libc_argv[p]; p++) { size_t len; char *s; if (w_addword (pwordexp, *word)) return WRDE_NOSPACE; len = strlen (__libc_argv[p]) + 1; s = malloc (len); if (s == NULL) return WRDE_NOSPACE; *word = memcpy (s, __libc_argv[p], len); *max_length = *word_length = len - 1; } } return 0; } value = getenv (env); if (action != ACT_NONE) { switch (action) { case ACT_RP_SHORT_LEFT: case ACT_RP_LONG_LEFT: case ACT_RP_SHORT_RIGHT: case ACT_RP_LONG_RIGHT: { char *p; char c; char *end; if (!pattern || !*pattern) break; end = value + strlen (value); if (value == NULL) break; switch (action) { case ACT_RP_SHORT_LEFT: for (p = value; p <= end; ++p) { c = *p; *p = '\0'; if (fnmatch (pattern, value, 0) != FNM_NOMATCH) { *p = c; value = p; break; } *p = c; } break; case ACT_RP_LONG_LEFT: for (p = end; p >= value; --p) { c = *p; *p = '\0'; if (fnmatch (pattern, value, 0) != FNM_NOMATCH) { *p = c; value = p; break; } *p = c; } break; case ACT_RP_SHORT_RIGHT: for (p = end; p >= value; --p) { if (fnmatch (pattern, p, 0) != FNM_NOMATCH) { *p = '\0'; break; } } break; case ACT_RP_LONG_RIGHT: for (p = value; p <= end; ++p) { if (fnmatch (pattern, p, 0) != FNM_NOMATCH) { *p = '\0'; break; } } break; default: break; } break; } case ACT_NULL_ERROR: if (value && *value) /* Substitute parameter */ break; if (!colon_seen && value) { /* Substitute NULL */ free (env); free (pattern); return 0; } if (*pattern) { /* Expand 'pattern' and write it to stderr */ wordexp_t we; error = wordexp (pattern, &we, flags); if (error == 0) { int i; fprintf (stderr, "%s:", env); for (i = 0; i < we.we_wordc; ++i) { fprintf (stderr, " %s", we.we_wordv[i]); } fprintf (stderr, "\n"); error = WRDE_BADVAL; } wordfree (&we); free (env); free (pattern); return error; } fprintf (stderr, "%s: parameter null or not set\n", env); free (env); free (pattern); return WRDE_BADVAL; case ACT_NULL_SUBST: if (value && *value) /* Substitute parameter */ break; if (!colon_seen && value) { /* Substitute NULL */ free (env); free (pattern); return 0; } subst_word: { /* Substitute word */ wordexp_t we; int i; if (quoted) { /* No field-splitting is allowed, so imagine quotes around the word. */ char *qtd_pattern = malloc (3 + strlen (pattern)); if (qtd_pattern) sprintf (qtd_pattern, "\"%s\"", pattern); free (pattern); pattern = qtd_pattern; } if (pattern == NULL && (pattern = __strdup ("")) == NULL) goto no_space; error = wordexp (pattern, &we, flags); if (error) { free (env); free (pattern); return error; } /* Fingers crossed that the quotes worked.. */ assert (!quoted || we.we_wordc == 1); /* Substitute */ for (i = 0; i < we.we_wordc; ++i) if (w_addword (pwordexp, __strdup (we.we_wordv[i])) == WRDE_NOSPACE) break; if (i < we.we_wordc) { /* Ran out of space */ wordfree (&we); goto no_space; } if (action == ACT_NULL_ASSIGN) { char *words; char *cp; size_t words_size = 0; for (i = 0; i < we.we_wordc; i++) words_size += strlen (we.we_wordv[i]) + 1; /* for */ words_size++; cp = words = __alloca (words_size); *words = 0; for (i = 0; i < we.we_wordc - 1; i++) { cp = __stpcpy (cp, we.we_wordv[i]); *cp++ = ' '; } __stpcpy (cp, we.we_wordv[i]); /* Also assign */ setenv (env, words, 1); } wordfree (&we); return 0; } case ACT_NONNULL_SUBST: if (value && *value) goto subst_word; if (!colon_seen && value) goto subst_word; /* Substitute NULL */ free (env); free (pattern); return 0; case ACT_NULL_ASSIGN: if (value && *value) /* Substitute parameter */ break; if (!colon_seen && value) { /* Substitute NULL */ free (env); free (pattern); return 0; } /* This checks for '=' so it knows to assign */ goto subst_word; default: assert (! "Unrecognised action!"); } } free (env); free (pattern); if (value == NULL) { /* Variable not defined */ if (flags & WRDE_UNDEF) return WRDE_BADVAL; return 0; } if (seen_hash) { char param_length[21]; param_length[20] = '\0'; *word = w_addstr (*word, word_length, max_length, _itoa_word (strlen (value), ¶m_length[20], 10, 0)); return *word ? 0 : WRDE_NOSPACE; } maybe_fieldsplit: if (quoted || !pwordexp) { /* Quoted - no field split */ *word = w_addstr (*word, word_length, max_length, value); if (free_value) free (value); return *word ? 0 : WRDE_NOSPACE; } else { /* Need to field-split */ char *value_copy = __strdup (value); /* Don't modify value */ char *field_begin = value_copy; int seen_nonws_ifs = 0; if (free_value) free (value); if (value_copy == NULL) return WRDE_NOSPACE; do { char *field_end = field_begin; char *next_field; /* If this isn't the first field, start a new word */ if (field_begin != value_copy) { if (w_addword (pwordexp, *word) == WRDE_NOSPACE) { free (value_copy); return WRDE_NOSPACE; } *word = NULL; *word_length = *max_length = 0; } /* Skip IFS whitespace before the field */ while (*field_begin && strchr (ifs_white, *field_begin) != NULL) field_begin++; if (!seen_nonws_ifs && *field_begin == 0) /* Nothing but whitespace */ break; /* Search for the end of the field */ field_end = field_begin; while (*field_end && strchr (ifs, *field_end) == NULL) field_end++; /* Set up pointer to the character after end of field */ next_field = *field_end ? field_end : NULL; /* Skip whitespace IFS after the field */ while (next_field && *next_field && strchr (ifs_white, *next_field)) next_field++; /* Skip at most one non-whitespace IFS character after the field */ seen_nonws_ifs = 0; if (next_field && *next_field && strchr (ifs, *next_field)) { seen_nonws_ifs = 1; next_field++; } /* Null-terminate it */ *field_end = 0; /* Tag a copy onto the current word */ *word = w_addstr (*word, word_length, max_length, field_begin); if (*word == NULL) { free (value_copy); return WRDE_NOSPACE; } field_begin = next_field; } while (seen_nonws_ifs || (field_begin != NULL && *field_begin)); free (value_copy); } return 0; no_space: if (env) free (env); if (pattern) free (pattern); return WRDE_NOSPACE; syntax: if (env) free (env); if (pattern) free (pattern); return WRDE_SYNTAX; } static int internal_function parse_dollars (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white, int quoted) { /* We are poised _at_ "$" */ switch (words[1 + *offset]) { case '"': case '\'': case 0: *word = w_addchar (*word, word_length, max_length, '$'); return *word ? 0 : WRDE_NOSPACE; case '(': if (words[2 + *offset] == '(') { /* Differentiate between $((1+3)) and $((echo);(ls)) */ int i = 3 + *offset; int depth = 0; while (words[i] && !(depth == 0 && words[i] == ')')) { if (words[i] == '(') ++depth; else if (words[i] == ')') --depth; ++i; } if (words[i] == ')' && words[i + 1] == ')') { (*offset) += 3; /* Call parse_arith -- 0 is for "no brackets" */ return parse_arith (word, word_length, max_length, words, offset, flags, 0); } } if (flags & WRDE_NOCMD) return WRDE_CMDSUB; (*offset) += 2; return parse_comm (word, word_length, max_length, words, offset, flags, quoted? NULL : pwordexp, ifs, ifs_white); case '[': (*offset) += 2; /* Call parse_arith -- 1 is for "brackets" */ return parse_arith (word, word_length, max_length, words, offset, flags, 1); case '{': default: ++(*offset); /* parse_param needs to know if "{" is there */ return parse_param (word, word_length, max_length, words, offset, flags, pwordexp, ifs, ifs_white, quoted); } } static int parse_backtick (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char *ifs, const char *ifs_white) { /* We are poised just after "`" */ int error; size_t comm_length = 0; size_t comm_maxlen = 0; char *comm = NULL; int squoting = 0; for (; words[*offset]; ++(*offset)) { switch (words[*offset]) { case '`': /* Go -- give the script to the shell */ error = exec_comm (comm, word, word_length, max_length, flags, pwordexp, ifs, ifs_white); free (comm); return error; case '\\': if (squoting) { error = parse_qtd_backslash (&comm, &comm_length, &comm_maxlen, words, offset); if (error) { free (comm); return error; } break; } ++(*offset); error = parse_backslash (&comm, &comm_length, &comm_maxlen, words, offset); if (error) { free (comm); return error; } break; case '\'': squoting = 1 - squoting; default: comm = w_addchar (comm, &comm_length, &comm_maxlen, words[*offset]); if (comm == NULL) return WRDE_NOSPACE; } } /* Premature end */ free (comm); return WRDE_SYNTAX; } static int internal_function parse_dquote (char **word, size_t *word_length, size_t *max_length, const char *words, size_t *offset, int flags, wordexp_t *pwordexp, const char * ifs, const char * ifs_white) { /* We are poised just after a double-quote */ int error; for (; words[*offset]; ++(*offset)) { switch (words[*offset]) { case '"': return 0; case '$': error = parse_dollars (word, word_length, max_length, words, offset, flags, pwordexp, ifs, ifs_white, 1); /* The ``1'' here is to tell parse_dollars not to * split the fields. It may need to, however ("$@"). */ if (error) return error; break; case '`': if (flags & WRDE_NOCMD) return WRDE_CMDSUB; ++(*offset); error = parse_backtick (word, word_length, max_length, words, offset, flags, NULL, NULL, NULL); /* The first NULL here is to tell parse_backtick not to * split the fields. */ if (error) return error; break; case '\\': error = parse_qtd_backslash (word, word_length, max_length, words, offset); if (error) return error; break; default: *word = w_addchar (*word, word_length, max_length, words[*offset]); if (*word == NULL) return WRDE_NOSPACE; } } /* Unterminated string */ return WRDE_SYNTAX; } /* * wordfree() is to be called after pwordexp is finished with. */ void wordfree (wordexp_t *pwordexp) { /* wordexp can set pwordexp to NULL */ if (pwordexp && pwordexp->we_wordv) { char **wordv = pwordexp->we_wordv; for (wordv += pwordexp->we_offs; *wordv; ++wordv) free (*wordv); free (pwordexp->we_wordv); pwordexp->we_wordv = NULL; } } /* * wordexp() */ int wordexp (const char *words, wordexp_t *pwordexp, int flags) { size_t wordv_offset; size_t words_offset; size_t word_length = 0; size_t max_length = 0; char *word = NULL; int error; char *ifs; char ifs_white[4]; char **old_wordv = pwordexp->we_wordv; size_t old_wordc = (flags & WRDE_REUSE) ? pwordexp->we_wordc : 0; if (flags & WRDE_REUSE) { /* Minimal implementation of WRDE_REUSE for now */ wordfree (pwordexp); old_wordv = NULL; } if (flags & WRDE_DOOFFS) { pwordexp->we_wordv = calloc (1 + pwordexp->we_offs, sizeof (char *)); if (pwordexp->we_wordv == NULL) return WRDE_NOSPACE; } else { pwordexp->we_wordv = calloc (1, sizeof (char *)); if (pwordexp->we_wordv == NULL) return WRDE_NOSPACE; pwordexp->we_offs = 0; } if ((flags & WRDE_APPEND) == 0) pwordexp->we_wordc = 0; wordv_offset = pwordexp->we_offs + pwordexp->we_wordc; /* Find out what the field separators are. * There are two types: whitespace and non-whitespace. */ ifs = getenv ("IFS"); if (!ifs) /* NULL IFS means no field-splitting is to be performed */ ifs = strcpy (ifs_white, ""); else { char *ifsch = ifs; char *whch = ifs_white; /* Start off with no whitespace IFS characters */ ifs_white[0] = '\0'; while (*ifsch != '\0') { if ((*ifsch == ' ') || (*ifsch == '\t') || (*ifsch == '\n')) { /* Whitespace IFS. See first whether it is already in our collection. */ char *runp = ifs_white; while (runp < whch && *runp != '\0' && *runp != *ifsch) ++runp; if (runp == whch) *whch++ = *ifsch; } ++ifsch; } *whch = '\0'; } for (words_offset = 0 ; words[words_offset] ; ++words_offset) switch (words[words_offset]) { case '\n': case '|': case '&': case ';': case '<': case '>': case '(': case ')': case '{': case '}': /* Fail */ wordfree (pwordexp); pwordexp->we_wordc = 0; pwordexp->we_wordv = old_wordv; return WRDE_BADCHAR; case '\\': error = parse_backslash (&word, &word_length, &max_length, words, &words_offset); if (error) goto do_error; break; case '$': error = parse_dollars (&word, &word_length, &max_length, words, &words_offset, flags, pwordexp, ifs, ifs_white, 0); if (error) goto do_error; break; case '`': if (flags & WRDE_NOCMD) return WRDE_CMDSUB; ++words_offset; error = parse_backtick (&word, &word_length, &max_length, words, &words_offset, flags, pwordexp, ifs, ifs_white); if (error) goto do_error; break; case '"': ++words_offset; error = parse_dquote (&word, &word_length, &max_length, words, &words_offset, flags, pwordexp, ifs, ifs_white); if (error) goto do_error; break; case '\'': ++words_offset; error = parse_squote (&word, &word_length, &max_length, words, &words_offset); if (error) goto do_error; break; case '~': error = parse_tilde (&word, &word_length, &max_length, words, &words_offset, pwordexp->we_wordc); if (error) goto do_error; break; case '*': case '[': case '?': error = parse_glob (&word, &word_length, &max_length, words, &words_offset, flags, pwordexp, ifs, ifs_white); if (error) goto do_error; break; default: /* Is it a field separator? */ if (strchr (ifs, words[words_offset]) == NULL) { /* "Ordinary" character -- add it to word */ word = w_addchar (word, &word_length, &max_length, words[words_offset]); if (word == NULL) { error = WRDE_NOSPACE; goto do_error; } break; } /* Field separator */ if (strchr (ifs_white, words[words_offset])) { /* It's a whitespace IFS char. Ignore it at the beginning of a line and ignore multiple instances. */ if (!word || !*word) break; if (w_addword (pwordexp, word) == WRDE_NOSPACE) { error = WRDE_NOSPACE; goto do_error; } word = NULL; word_length = 0; max_length = 0; break; } /* It's a non-whitespace IFS char */ /* Multiple non-whitespace IFS chars are treated as one; * IS THIS CORRECT? */ if (word != NULL) { if (w_addword (pwordexp, word) == WRDE_NOSPACE) { error = WRDE_NOSPACE; goto do_error; } } word = NULL; word_length = 0; max_length = 0; } /* End of string */ /* There was a field separator at the end */ if (word == NULL) return 0; /* There was no field separator at the end */ return w_addword (pwordexp, word); do_error: /* Error: * free memory used (unless error is WRDE_NOSPACE), and * set we_wordc and wd_wordv back to what they were. */ if (error == WRDE_NOSPACE) return WRDE_NOSPACE; if (word != NULL) free (word); wordfree (pwordexp); pwordexp->we_wordv = old_wordv; pwordexp->we_wordc = old_wordc; return error; }