diff options
author | Tom Gundersen <teg@jklm.no> | 2015-10-25 14:22:43 +0100 |
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committer | Tom Gundersen <teg@jklm.no> | 2015-10-25 14:22:43 +0100 |
commit | 7c8871d31510865e40c8628ef765996202a3cc00 (patch) | |
tree | 622b7aa085999fe3d2908772ff0d0c6ec5bf4400 /src/basic/extract-word.c | |
parent | 7c257428969aaba2acc4e26753c86d6f4774354a (diff) | |
parent | f00022dd121c73b543ae667ddce9814bd67a1b73 (diff) |
Merge pull request #1654 from poettering/util-lib
Various changes to src/basic/
Diffstat (limited to 'src/basic/extract-word.c')
-rw-r--r-- | src/basic/extract-word.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c new file mode 100644 index 0000000000..f2b74802fa --- /dev/null +++ b/src/basic/extract-word.c @@ -0,0 +1,284 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "escape.h" +#include "utf8.h" +#include "util.h" +#include "extract-word.h" + +int extract_first_word(const char **p, char **ret, const char *separators, ExtractFlags flags) { + _cleanup_free_ char *s = NULL; + size_t allocated = 0, sz = 0; + int r; + + char quote = 0; /* 0 or ' or " */ + bool backslash = false; /* whether we've just seen a backslash */ + bool separator = false; /* whether we've just seen a separator */ + bool start = true; /* false means we're looking at a value */ + + assert(p); + assert(ret); + + if (!separators) + separators = WHITESPACE; + + /* Bail early if called after last value or with no input */ + if (!*p) + goto finish_force_terminate; + + /* Parses the first word of a string, and returns it in + * *ret. Removes all quotes in the process. When parsing fails + * (because of an uneven number of quotes or similar), leaves + * the pointer *p at the first invalid character. */ + + for (;;) { + char c = **p; + + if (start) { + if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) + if (!GREEDY_REALLOC(s, allocated, sz+1)) + return -ENOMEM; + + if (c == 0) + goto finish_force_terminate; + else if (strchr(separators, c)) { + (*p) ++; + if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) + goto finish_force_next; + continue; + } + + /* We found a non-blank character, so we will always + * want to return a string (even if it is empty), + * allocate it here. */ + if (!GREEDY_REALLOC(s, allocated, sz+1)) + return -ENOMEM; + + start = false; + } + + if (backslash) { + if (!GREEDY_REALLOC(s, allocated, sz+7)) + return -ENOMEM; + + if (c == 0) { + if ((flags & EXTRACT_CUNESCAPE_RELAX) && + (!quote || flags & EXTRACT_RELAX)) { + /* If we find an unquoted trailing backslash and we're in + * EXTRACT_CUNESCAPE_RELAX mode, keep it verbatim in the + * output. + * + * Unbalanced quotes will only be allowed in EXTRACT_RELAX + * mode, EXTRACT_CUNESCAPE_RELAX mode does not allow them. + */ + s[sz++] = '\\'; + goto finish_force_terminate; + } + if (flags & EXTRACT_RELAX) + goto finish_force_terminate; + return -EINVAL; + } + + if (flags & EXTRACT_CUNESCAPE) { + uint32_t u; + + r = cunescape_one(*p, (size_t) -1, &c, &u); + if (r < 0) { + if (flags & EXTRACT_CUNESCAPE_RELAX) { + s[sz++] = '\\'; + s[sz++] = c; + goto end_escape; + } + return -EINVAL; + } + + (*p) += r - 1; + + if (c != 0) + s[sz++] = c; /* normal explicit char */ + else + sz += utf8_encode_unichar(s + sz, u); /* unicode chars we'll encode as utf8 */ + } else + s[sz++] = c; + +end_escape: + backslash = false; + + } else if (quote) { /* inside either single or double quotes */ + if (c == 0) { + if (flags & EXTRACT_RELAX) + goto finish_force_terminate; + return -EINVAL; + } else if (c == quote) /* found the end quote */ + quote = 0; + else if (c == '\\') + backslash = true; + else { + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + } + + } else if (separator) { + if (c == 0) + goto finish_force_terminate; + if (!strchr(separators, c)) + goto finish; + + } else { + if (c == 0) + goto finish_force_terminate; + else if ((c == '\'' || c == '"') && (flags & EXTRACT_QUOTES)) + quote = c; + else if (c == '\\') + backslash = true; + else if (strchr(separators, c)) { + if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) { + (*p) ++; + goto finish_force_next; + } + separator = true; + } else { + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + } + } + + (*p) ++; + } + +finish_force_terminate: + *p = NULL; +finish: + if (!s) { + *p = NULL; + *ret = NULL; + return 0; + } + +finish_force_next: + s[sz] = 0; + *ret = s; + s = NULL; + + return 1; +} + +int extract_first_word_and_warn( + const char **p, + char **ret, + const char *separators, + ExtractFlags flags, + const char *unit, + const char *filename, + unsigned line, + const char *rvalue) { + + /* Try to unquote it, if it fails, warn about it and try again + * but this time using EXTRACT_CUNESCAPE_RELAX to keep the + * backslashes verbatim in invalid escape sequences. */ + + const char *save; + int r; + + save = *p; + r = extract_first_word(p, ret, separators, flags); + if (r >= 0) + return r; + + if (r == -EINVAL && !(flags & EXTRACT_CUNESCAPE_RELAX)) { + + /* Retry it with EXTRACT_CUNESCAPE_RELAX. */ + *p = save; + r = extract_first_word(p, ret, separators, flags|EXTRACT_CUNESCAPE_RELAX); + if (r >= 0) { + /* It worked this time, hence it must have been an invalid escape sequence we could correct. */ + log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Invalid escape sequences in line, correcting: \"%s\"", rvalue); + return r; + } + + /* If it's still EINVAL; then it must be unbalanced quoting, report this. */ + if (r == -EINVAL) + return log_syntax(unit, LOG_ERR, filename, line, r, "Unbalanced quoting, ignoring: \"%s\"", rvalue); + } + + /* Can be any error, report it */ + return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue); +} + +int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) { + va_list ap; + char **l; + int n = 0, i, c, r; + + /* Parses a number of words from a string, stripping any + * quotes if necessary. */ + + assert(p); + + /* Count how many words are expected */ + va_start(ap, flags); + for (;;) { + if (!va_arg(ap, char **)) + break; + n++; + } + va_end(ap); + + if (n <= 0) + return 0; + + /* Read all words into a temporary array */ + l = newa0(char*, n); + for (c = 0; c < n; c++) { + + r = extract_first_word(p, &l[c], separators, flags); + if (r < 0) { + int j; + + for (j = 0; j < c; j++) + free(l[j]); + + return r; + } + + if (r == 0) + break; + } + + /* If we managed to parse all words, return them in the passed + * in parameters */ + va_start(ap, flags); + for (i = 0; i < n; i++) { + char **v; + + v = va_arg(ap, char **); + assert(v); + + *v = l[i]; + } + va_end(ap); + + return c; +} |