/* vi: set sw=4 ts=4: */ /* POSIX.2 wordexp implementation. Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Tim Waugh <tim@cyberelk.demon.co.uk>. 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. */ #define _GNU_SOURCE #include <sys/cdefs.h> #include <sys/types.h> #include <sys/wait.h> #include <fcntl.h> #include <paths.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <pwd.h> #include <errno.h> #include <assert.h> #include <fnmatch.h> #include <glob.h> #include <wordexp.h> #define __WORDEXP_FULL //#undef __WORDEXP_FULL /* * 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; /* FIXME!!!! */ int __libc_argc; 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); 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); 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); /* The w_*() functions manipulate word lists. */ #define W_CHUNK (100) /* Result of w_newword will be ignored if it's the last word. */ static inline char *w_newword(size_t * actlen, size_t * maxlen) { *actlen = *maxlen = 0; return NULL; } /* Add a character to the buffer, allocating room for it if needed. */ static inline char *w_addchar(char *buffer, size_t * actlen, size_t * maxlen, char ch) /* (lengths exclude trailing zero) */ { 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; } #define MAX( a, b ) ( ( ( a ) > ( b ) ) ? ( a ) : ( b ) ) static char *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; } /* Add a string to the buffer, allocating room for it if needed. */ static char *w_addstr(char *buffer, size_t * actlen, size_t * maxlen, const char *str) /* (lengths exclude trailing zero) */ { size_t len; assert(str != NULL); /* w_addstr only called from this file */ len = strlen(str); return w_addmem(buffer, actlen, maxlen, str, len); } /* Add a word to the wordlist */ static int w_addword(wordexp_t * pwordexp, char *word) { size_t num_p; char **new_wordv; /* Internally, NULL acts like "". Convert NULLs to "" before * the caller sees them. */ if (word == NULL) { word = strdup(""); if (word == NULL) goto no_space; } 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_offs + pwordexp->we_wordc++] = word; pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc] = NULL; return 0; } no_space: return WRDE_NOSPACE; } /* The parse_*() functions should leave *offset being the offset in 'words' * to the last character processed. */ static int 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 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 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 *home; char *buffer; int result; /* POSIX.2 says ~ expands to $HOME and if HOME is unset the results are unspecified. We do a lookup on the uid if HOME is unset. */ home = getenv("HOME"); if (home != NULL) { *word = w_addstr(*word, word_length, max_length, home); if (*word == NULL) return WRDE_NOSPACE; } else { uid = getuid(); buffer = alloca(buflen); while ((result = getpwuid_r(uid, &pwd, buffer, buflen, &tpwd)) != 0 && errno == ERANGE) { buflen += 1000; buffer = alloca(buflen); } if (result == 0 && tpwd != NULL && 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 - (1 + *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 && tpwd != NULL && 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 do_parse_glob(const char *glob_word, char **word, size_t * word_length, size_t * max_length, wordexp_t * pwordexp, const char *ifs, const char *ifs_white) { int error; int match; glob_t globbuf; error = glob(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. */ assert(globbuf.gl_pathv[0] != NULL); *word = w_addstr(*word, word_length, max_length, globbuf.gl_pathv[0]); 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]); } globfree(&globbuf); return *word ? 0 : WRDE_NOSPACE; } assert(ifs == NULL || *ifs != '\0'); if (*word != NULL) { free(*word); *word = w_newword(word_length, max_length); } for (match = 0; match < globbuf.gl_pathc; ++match) { char *matching_word = strdup(globbuf.gl_pathv[match]); if (matching_word == NULL || w_addword(pwordexp, matching_word)) { globfree(&globbuf); return WRDE_NOSPACE; } } globfree(&globbuf); return 0; } static int 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 = WRDE_NOSPACE; int quoted = 0; /* 1 if singly-quoted, 2 if doubly */ int i; wordexp_t glob_list; /* List of words to glob */ glob_list.we_wordc = 0; glob_list.we_wordv = NULL; glob_list.we_offs = 0; for (; words[*offset] != '\0'; ++*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, &glob_list, ifs, ifs_white, quoted == 2); if (error) goto tidy_up; 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) goto tidy_up; continue; } *word = w_addchar(*word, word_length, max_length, words[*offset]); if (*word == NULL) goto tidy_up; } /* Don't forget to re-parse the character we stopped at. */ --*offset; /* Glob the words */ error = w_addword(&glob_list, *word); *word = w_newword(word_length, max_length); for (i = 0; error == 0 && i < glob_list.we_wordc; i++) error = do_parse_glob(glob_list.we_wordv[i], word, word_length, max_length, pwordexp, ifs, ifs_white); /* Now tidy up */ tidy_up: wordfree(&glob_list); return error; } static int 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; } #ifdef __WORDEXP_FULL static int eval_expr(char *expr, long int *result); static char *_itoa(unsigned long long int value, char *buflim) { sprintf(buflim, "%llu", value); return buflim; } /* Functions to evaluate an arithmetic expression */ static int 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 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 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 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; size_t expr_maxlen; char *expr; expr = w_newword(&expr_length, &expr_maxlen); 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] != ')') { free(expr); return WRDE_SYNTAX; } ++(*offset); /* Go - evaluate. */ if (*expr && eval_expr(expr, &numresult) != 0) { free(expr); 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])); 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) { free(expr); return WRDE_SYNTAX; } result[20] = '\0'; *word = w_addstr(*word, word_length, max_length, _itoa(numresult, &result[20])); 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 called by child process in exec_comm() */ static void exec_comm_child(char *comm, int *fildes, int showerr, int noexec) { const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL }; /* Execute the command, or just check syntax? */ if (noexec) args[1] = "-nc"; /* Redirect output. */ dup2(fildes[1], 1); close(fildes[1]); /* Redirect stderr to /dev/null if we have to. */ if (showerr == 0) { int fd; close(2); fd = open(_PATH_DEVNULL, O_WRONLY); if (fd >= 0 && fd != 2) { dup2(fd, 2); close(fd); } } /* Make sure the subshell doesn't field-split on our behalf. */ unsetenv("IFS"); close(fildes[0]); execve(_PATH_BSHELL, (char *const *) args, __environ); /* Bad. What now? */ abort(); } /* Function to execute a command and retrieve the results */ /* pwordexp contains NULL if field-splitting is forbidden */ static int 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; int status = 0; size_t maxnewlines = 0; 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 */ close(fildes[0]); close(fildes[1]); return WRDE_NOSPACE; } if (pid == 0) exec_comm_child(comm, fildes, (flags & WRDE_SHOWERR), 0); /* 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, &status, WNOHANG) == 0) continue; if ((buflen = read(fildes[0], buffer, bufsize)) < 1) break; } maxnewlines += buflen; *word = w_addmem(*word, word_length, max_length, buffer, buflen); if (*word == NULL) goto no_space; } } 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 * 3 when searching for non-newline after copying field */ while (1) { if ((buflen = read(fildes[0], buffer, bufsize)) < 1) { if (waitpid(pid, &status, WNOHANG) == 0) continue; if ((buflen = 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: text<space><comma><space>moretext * * So, strip whitespace IFS (like at the start) */ copying = 0; continue; } copying = 0; /* fall through and delimit field.. */ } else { if (buffer[i] == '\n') { /* Current character is (IFS) newline */ /* If copying a field, this is the end of it, but maybe all that's left is trailing newlines. So start searching for a non-newline. */ if (copying == 1) copying = 3; continue; } else { /* Current character is IFS white space, but not a newline */ /* If not either copying a field or searching for non-newline after a field, ignore it */ if (copying != 1 && copying != 3) continue; /* End of field (search for non-ws IFS afterwards) */ copying = 2; } } /* First IFS white space (non-newline), or IFS non-whitespace. * Delimit the field. Nulls are converted by w_addword. */ if (w_addword(pwordexp, *word) == WRDE_NOSPACE) goto no_space; *word = w_newword(word_length, max_length); maxnewlines = 0; /* fall back round the loop.. */ } else { /* Not IFS character */ if (copying == 3) { /* Nothing but (IFS) newlines since the last field, so delimit it here before starting new word */ if (w_addword(pwordexp, *word) == WRDE_NOSPACE) goto no_space; *word = w_newword(word_length, max_length); } copying = 1; if (buffer[i] == '\n') /* happens if newline not in IFS */ maxnewlines++; else maxnewlines = 0; *word = w_addchar(*word, word_length, max_length, buffer[i]); if (*word == NULL) goto no_space; } } } } /* Chop off trailing newlines (required by POSIX.2) */ /* Ensure we don't go back further than the beginning of the substitution (i.e. remove maxnewlines bytes at most) */ while (maxnewlines-- != 0 && *word_length > 0 && (*word)[*word_length - 1] == '\n') { (*word)[--*word_length] = '\0'; /* If the last word was entirely newlines, turn it into a new word * which can be ignored if there's nothing following it. */ if (*word_length == 0) { free(*word); *word = w_newword(word_length, max_length); break; } } close(fildes[0]); /* Check for syntax error (re-execute but with "-n" flag) */ if (buflen < 1 && status != 0) { if ((pid = fork()) < 0) { /* Bad */ return WRDE_NOSPACE; } if (pid == 0) { fildes[0] = fildes[1] = -1; exec_comm_child(comm, fildes, 0, 1); } if (waitpid(pid, &status, 0) == pid && status != 0) return WRDE_SYNTAX; } return 0; no_space: kill(pid, SIGKILL); waitpid(pid, NULL, 0); close(fildes[0]); return WRDE_NOSPACE; } static int 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; int quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */ size_t comm_length; size_t comm_maxlen; char *comm = w_newword(&comm_length, &comm_maxlen); 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 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; int squoting = 0; size_t comm_length; size_t comm_maxlen; char *comm = w_newword(&comm_length, &comm_maxlen); 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 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 "$" */ enum action { ACT_NONE, ACT_RP_SHORT_LEFT = '#', ACT_RP_LONG_LEFT = 'L', ACT_RP_SHORT_RIGHT = '%', ACT_RP_LONG_RIGHT = 'R', ACT_NULL_ERROR = '?', ACT_NULL_SUBST = '-', ACT_NONNULL_SUBST = '+', ACT_NULL_ASSIGN = '=' }; size_t env_length; size_t env_maxlen; size_t pat_length; size_t pat_maxlen; size_t start = *offset; char *env; char *pattern; char *value = NULL; enum action action = ACT_NONE; int depth = 0; int colon_seen = 0; int seen_hash = 0; int free_value = 0; int pattern_is_quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */ int error; int special = 0; char buffer[21]; int brace = words[*offset] == '{'; env = w_newword(&env_length, &env_maxlen); pattern = w_newword(&pat_length, &pat_maxlen); if (brace) ++ * offset; /* First collect the parameter name. */ if (words[*offset] == '#') { seen_hash = 1; if (!brace) goto envsubst; ++*offset; } if (isalpha(words[*offset]) || words[*offset] == '_') { /* Normal parameter name. */ do { env = w_addchar(env, &env_length, &env_maxlen, words[*offset]); if (env == NULL) goto no_space; } while (isalnum(words[++*offset]) || words[*offset] == '_'); } else if (isdigit(words[*offset])) { /* Numeric parameter name. */ special = 1; do { env = w_addchar(env, &env_length, &env_maxlen, words[*offset]); if (env == NULL) goto no_space; if (!brace) goto envsubst; } while (isdigit(words[++*offset])); } else if (strchr("*@$", words[*offset]) != NULL) { /* Special parameter. */ special = 1; env = w_addchar(env, &env_length, &env_maxlen, words[*offset]); if (env == NULL) goto no_space; ++*offset; } else { if (brace) goto syntax; } if (brace) { /* Check for special action to be applied to the value. */ switch (words[*offset]) { case '}': /* Evaluate. */ goto envsubst; case '#': action = ACT_RP_SHORT_LEFT; if (words[1 + *offset] == '#') { ++*offset; action = ACT_RP_LONG_LEFT; } break; case '%': action = ACT_RP_SHORT_RIGHT; if (words[1 + *offset] == '%') { ++*offset; action = ACT_RP_LONG_RIGHT; } break; case ':': if (strchr("-=?+", words[1 + *offset]) == NULL) goto syntax; colon_seen = 1; action = words[++*offset]; break; case '-': case '=': case '?': case '+': action = words[*offset]; break; default: goto syntax; } /* Now collect the pattern, but don't expand it yet. */ ++*offset; for (; words[*offset]; ++(*offset)) { 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) /* Quoted; treat as normal character. */ break; /* Otherwise, it's an escape: next character is literal. */ if (words[++*offset] == '\0') goto syntax; pattern = w_addchar(pattern, &pat_length, &pat_maxlen, '\\'); if (pattern == NULL) goto no_space; 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; } } /* End of input string -- remember to reparse the character that we * stopped at. */ --(*offset); envsubst: if (words[start] == '{' && words[*offset] != '}') goto syntax; if (env == NULL) { if (seen_hash) { /* $# expands to the number of positional parameters */ buffer[20] = '\0'; value = _itoa(__libc_argc - 1, &buffer[20]); seen_hash = 0; } else { /* Just $ on its own */ *offset = start - 1; *word = w_addchar(*word, word_length, max_length, '$'); return *word ? 0 : WRDE_NOSPACE; } } /* Is it a numeric parameter? */ else if (isdigit(env[0])) { int n = atoi(env); if (n >= __libc_argc) /* Substitute NULL. */ value = NULL; else /* Replace with appropriate positional parameter. */ value = __libc_argv[n]; } /* Is it a special parameter? */ else if (special) { /* Is it `$$'? */ if (*env == '$') { buffer[20] = '\0'; value = _itoa(getpid(), &buffer[20]); } /* Is it `${#*}' or `${#@}'? */ else if ((*env == '*' || *env == '@') && seen_hash) { buffer[20] = '\0'; value = _itoa(__libc_argc > 0 ? __libc_argc - 1 : 0, &buffer[20]); *word = w_addstr(*word, word_length, max_length, value); free(env); if (pattern) free(pattern); return *word ? 0 : WRDE_NOSPACE; } /* Is it `$*' or `$@' (unquoted) ? */ else if (*env == '*' || (*env == '@' && !quoted)) { size_t plist_len = 0; int p; char *end; /* Build up value parameter by parameter (copy them) */ for (p = 1; __libc_argv[p]; ++p) plist_len += strlen(__libc_argv[p]) + 1; /* for space */ value = malloc(plist_len); if (value == NULL) goto no_space; end = value; *end = 0; for (p = 1; __libc_argv[p]; ++p) { if (p > 1) *end++ = ' '; end = stpcpy(end, __libc_argv[p]); } free_value = 1; } else { /* Must be a quoted `$@' */ assert(*env == '@' && quoted); /* Each parameter is a separate word ("$@") */ if (__libc_argc == 2) value = __libc_argv[1]; else if (__libc_argc > 2) { int p; /* Append first parameter to current word. */ value = w_addstr(*word, word_length, max_length, __libc_argv[1]); if (value == NULL || w_addword(pwordexp, value)) goto no_space; for (p = 2; __libc_argv[p + 1]; p++) { char *newword = strdup(__libc_argv[p]); if (newword == NULL || w_addword(pwordexp, newword)) goto no_space; } /* Start a new word with the last parameter. */ *word = w_newword(word_length, max_length); value = __libc_argv[p]; } else { free(env); free(pattern); return 0; } } } else value = getenv(env); if (value == NULL && (flags & WRDE_UNDEF)) { /* Variable not defined. */ error = WRDE_BADVAL; goto do_error; } if (action != ACT_NONE) { int expand_pattern = 0; /* First, find out if we need to expand pattern (i.e. if we will * use it). */ switch (action) { case ACT_RP_SHORT_LEFT: case ACT_RP_LONG_LEFT: case ACT_RP_SHORT_RIGHT: case ACT_RP_LONG_RIGHT: /* Always expand for these. */ expand_pattern = 1; break; case ACT_NULL_ERROR: case ACT_NULL_SUBST: case ACT_NULL_ASSIGN: if (!value || (!*value && colon_seen)) /* If param is unset, or set but null and a colon has been seen, the expansion of the pattern will be needed. */ expand_pattern = 1; break; case ACT_NONNULL_SUBST: /* Expansion of word will be needed if parameter is set and not null, or set null but no colon has been seen. */ if (value && (*value || !colon_seen)) expand_pattern = 1; break; default: assert(!"Unrecognised action!"); } if (expand_pattern) { /* We need to perform tilde expansion, parameter expansion, command substitution, and arithmetic expansion. We also have to be a bit careful with wildcard characters, as pattern might be given to fnmatch soon. To do this, we convert quotes to escapes. */ char *expanded; size_t exp_len; size_t exp_maxl; char *p; int quoted = 0; /* 1: single quotes; 2: double */ expanded = w_newword(&exp_len, &exp_maxl); for (p = pattern; p && *p; p++) { size_t offset; switch (*p) { case '"': if (quoted == 2) quoted = 0; else if (quoted == 0) quoted = 2; else break; continue; case '\'': if (quoted == 1) quoted = 0; else if (quoted == 0) quoted = 1; else break; continue; case '*': case '?': if (quoted) { /* Convert quoted wildchar to escaped wildchar. */ expanded = w_addchar(expanded, &exp_len, &exp_maxl, '\\'); if (expanded == NULL) goto no_space; } break; case '$': offset = 0; error = parse_dollars(&expanded, &exp_len, &exp_maxl, p, &offset, flags, NULL, NULL, NULL, 1); if (error) { if (free_value) free(value); if (expanded) free(expanded); goto do_error; } p += offset; continue; case '~': if (quoted || exp_len) break; offset = 0; error = parse_tilde(&expanded, &exp_len, &exp_maxl, p, &offset, 0); if (error) { if (free_value) free(value); if (expanded) free(expanded); goto do_error; } p += offset; continue; case '\\': expanded = w_addchar(expanded, &exp_len, &exp_maxl, '\\'); ++p; assert(*p); /* checked when extracted initially */ if (expanded == NULL) goto no_space; } expanded = w_addchar(expanded, &exp_len, &exp_maxl, *p); if (expanded == NULL) goto no_space; } if (pattern) free(pattern); pattern = expanded; } 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 (value == NULL || pattern == NULL || *pattern == '\0') break; end = value + strlen(value); 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; if (free_value) { char *newval = strdup(p); if (newval == NULL) { free(value); goto no_space; } free(value); value = newval; } else 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; if (free_value) { char *newval = strdup(p); if (newval == NULL) { free(value); goto no_space; } free(value); value = newval; } else value = p; break; } *p = c; } break; case ACT_RP_SHORT_RIGHT: for (p = end; p >= value; --p) { if (fnmatch(pattern, p, 0) != FNM_NOMATCH) { char *newval; newval = malloc(p - value + 1); if (newval == NULL) { if (free_value) free(value); goto no_space; } *(char *) mempcpy(newval, value, p - value) = '\0'; if (free_value) free(value); value = newval; free_value = 1; break; } } break; case ACT_RP_LONG_RIGHT: for (p = value; p <= end; ++p) { if (fnmatch(pattern, p, 0) != FNM_NOMATCH) { char *newval; newval = malloc(p - value + 1); if (newval == NULL) { if (free_value) free(value); goto no_space; } *(char *) mempcpy(newval, value, p - value) = '\0'; if (free_value) free(value); value = newval; free_value = 1; break; } } break; default: break; } break; } case ACT_NULL_ERROR: if (value && *value) /* Substitute parameter */ break; error = 0; if (!colon_seen && value) /* Substitute NULL */ ; else if (*pattern) fprintf(stderr, "%s: %s\n", env, pattern); else { fprintf(stderr, "%s: parameter null or not set\n", env); error = WRDE_BADVAL; } if (free_value) free(value); goto do_error; case ACT_NULL_SUBST: if (value && *value) /* Substitute parameter */ break; if (free_value && value) free(value); if (!colon_seen && value) /* Substitute NULL */ goto success; value = pattern ? strdup(pattern) : pattern; free_value = 1; if (pattern && !value) goto no_space; break; case ACT_NONNULL_SUBST: if (value && (*value || !colon_seen)) { if (free_value && value) free(value); value = pattern ? strdup(pattern) : pattern; free_value = 1; if (pattern && !value) goto no_space; break; } /* Substitute NULL */ if (free_value) free(value); goto success; case ACT_NULL_ASSIGN: if (value && *value) /* Substitute parameter */ break; if (!colon_seen && value) { /* Substitute NULL */ if (free_value) free(value); goto success; } if (free_value && value) free(value); value = pattern ? strdup(pattern) : pattern; free_value = 1; if (pattern && !value) goto no_space; setenv(env, value, 1); break; default: assert(!"Unrecognised action!"); } } free(env); env = NULL; free(pattern); pattern = NULL; if (seen_hash) { char param_length[21]; param_length[20] = '\0'; *word = w_addstr(*word, word_length, max_length, _itoa(value ? strlen(value) : 0, ¶m_length[20])); if (free_value) { assert(value != NULL); free(value); } return *word ? 0 : WRDE_NOSPACE; } if (value == NULL) return 0; 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) goto no_space; 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); goto no_space; } *word = w_newword(word_length, max_length); } /* Skip IFS whitespace before the field */ field_begin += strspn(field_begin, ifs_white); if (!seen_nonws_ifs && *field_begin == 0) /* Nothing but whitespace */ break; /* Search for the end of the field */ field_end = field_begin + strcspn(field_begin, ifs); /* Set up pointer to the character after end of field and skip whitespace IFS after it. */ next_field = field_end + strspn(field_end, ifs_white); /* Skip at most one non-whitespace IFS character after the field */ seen_nonws_ifs = 0; if (*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 && *field_begin != '\0') { free(value_copy); goto no_space; } field_begin = next_field; } while (seen_nonws_ifs || *field_begin); free(value_copy); } return 0; success: error = 0; goto do_error; no_space: error = WRDE_NOSPACE; goto do_error; syntax: error = WRDE_SYNTAX; do_error: if (env) free(env); if (pattern) free(pattern); return error; } #else static inline 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) { return 0; } #endif 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) { /* 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; #ifdef __WORDEXP_FULL case '(': if (words[2 + *offset] == '(') { /* Differentiate between $((1+3)) and $((echo);(ls)) */ int i = 3 + *offset; int depth = 0; while (words[i] && !(depth == 0 && words[i] == ')')) { if (words[i] == '(') ++depth; else if (words[i] == ')') --depth; ++i; } if (words[i] == ')' && words[i + 1] == ')') { (*offset) += 3; /* Call parse_arith -- 0 is for "no brackets" */ return parse_arith(word, word_length, max_length, words, offset, flags, 0); } } if (flags & WRDE_NOCMD) return WRDE_CMDSUB; (*offset) += 2; return parse_comm(word, word_length, max_length, words, offset, flags, quoted ? NULL : pwordexp, ifs, ifs_white); case '[': (*offset) += 2; /* Call parse_arith -- 1 is for "brackets" */ return parse_arith(word, word_length, max_length, words, offset, flags, 1); case '{': default: ++(*offset); /* parse_param needs to know if "{" is there */ return parse_param(word, word_length, max_length, words, offset, flags, pwordexp, ifs, ifs_white, quoted); #else default: ++(*offset); /* parse_param needs to know if "{" is there */ return 0; #endif } } static int parse_dquote(char **word, size_t * word_length, size_t * max_length, const char *words, size_t * offset, int flags, wordexp_t * pwordexp, const char *ifs, const char *ifs_white) { /* We are poised just after a double-quote */ int error; for (; words[*offset]; ++(*offset)) { switch (words[*offset]) { case '"': return 0; case '$': 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 * we, int flags) { size_t words_offset; size_t word_length; size_t max_length; char *word = w_newword(&word_length, &max_length); int error; char *ifs; char ifs_white[4]; wordexp_t old_word = *we; if (flags & WRDE_REUSE) { /* Minimal implementation of WRDE_REUSE for now */ wordfree(we); old_word.we_wordv = NULL; } if ((flags & WRDE_APPEND) == 0) { we->we_wordc = 0; if (flags & WRDE_DOOFFS) { we->we_wordv = calloc(1 + we->we_offs, sizeof(char *)); if (we->we_wordv == NULL) { error = WRDE_NOSPACE; goto do_error; } } else { we->we_wordv = calloc(1, sizeof(char *)); if (we->we_wordv == NULL) { error = WRDE_NOSPACE; goto do_error; } we->we_offs = 0; } } /* Find out what the field separators are. * There are two types: whitespace and non-whitespace. */ ifs = getenv("IFS"); if (!ifs) /* IFS unset - use <space><tab><newline>. */ ifs = strcpy(ifs_white, " \t\n"); 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 '\\': 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, we, ifs, ifs_white, 0); if (error) goto do_error; break; case '`': if (flags & WRDE_NOCMD) { error = WRDE_CMDSUB; goto do_error; } ++words_offset; error = parse_backtick(&word, &word_length, &max_length, words, &words_offset, flags, we, ifs, ifs_white); if (error) goto do_error; break; case '"': ++words_offset; error = parse_dquote(&word, &word_length, &max_length, words, &words_offset, flags, we, ifs, ifs_white); if (error) goto do_error; if (!word_length) { error = w_addword(we, NULL); if (error) return error; } break; case '\'': ++words_offset; error = parse_squote(&word, &word_length, &max_length, words, &words_offset); if (error) goto do_error; if (!word_length) { error = w_addword(we, NULL); if (error) return error; } break; case '~': error = parse_tilde(&word, &word_length, &max_length, words, &words_offset, we->we_wordc); if (error) goto do_error; break; case '*': case '[': case '?': error = parse_glob(&word, &word_length, &max_length, words, &words_offset, flags, we, ifs, ifs_white); if (error) goto do_error; break; default: /* Is it a word separator? */ if (strchr(" \t", words[words_offset]) == NULL) { char ch = words[words_offset]; /* Not a word separator -- but is it a valid word char? */ if (strchr("\n|&;<>(){}", ch)) { /* Fail */ error = WRDE_BADCHAR; goto do_error; } /* "Ordinary" character -- add it to word */ word = w_addchar(word, &word_length, &max_length, ch); if (word == NULL) { error = WRDE_NOSPACE; goto do_error; } break; } /* If a word has been delimited, add it to the list. */ if (word != NULL) { error = w_addword(we, word); if (error) goto do_error; } word = w_newword(&word_length, &max_length); } /* End of string */ /* There was a word separator at the end */ if (word == NULL) /* i.e. w_newword */ return 0; /* There was no field separator at the end */ return w_addword(we, word); do_error: /* Error: * free memory used (unless error is WRDE_NOSPACE), and * set we members back to what they were. */ if (word != NULL) free(word); if (error == WRDE_NOSPACE) return WRDE_NOSPACE; if ((flags & WRDE_APPEND) == 0) wordfree(we); *we = old_word; return error; }