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-rw-r--r--lib/compat/fnmatch.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/lib/compat/fnmatch.c b/lib/compat/fnmatch.c
new file mode 100644
index 0000000..ed4dde1
--- /dev/null
+++ b/lib/compat/fnmatch.c
@@ -0,0 +1,305 @@
+/*
+ * An implementation of what I call the "Sea of Stars" algorithm for
+ * POSIX fnmatch(). The basic idea is that we factor the pattern into
+ * a head component (which we match first and can reject without ever
+ * measuring the length of the string), an optional tail component
+ * (which only exists if the pattern contains at least one star), and
+ * an optional "sea of stars", a set of star-separated components
+ * between the head and tail. After the head and tail matches have
+ * been removed from the input string, the components in the "sea of
+ * stars" are matched sequentially by searching for their first
+ * occurrence past the end of the previous match.
+ *
+ * - Rich Felker, April 2012
+ */
+
+#include "compat.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+#ifndef HAVE_FNMATCH
+#define END 0
+#define UNMATCHABLE -2
+#define BRACKET -3
+#define QUESTION -4
+#define STAR -5
+
+static int str_next(const char *str, size_t n, size_t *step)
+{
+ if (!n) {
+ *step = 0;
+ return 0;
+ }
+ if (str[0] >= 128U) {
+ wchar_t wc;
+ int k = mbtowc(&wc, str, n);
+ if (k<0) {
+ *step = 1;
+ return -1;
+ }
+ *step = k;
+ return wc;
+ }
+ *step = 1;
+ return str[0];
+}
+
+static int pat_next(const char *pat, size_t m, size_t *step)
+{
+ int esc = 0;
+ if (!m || !*pat) {
+ *step = 0;
+ return END;
+ }
+ *step = 1;
+ if (pat[0]=='\\' && pat[1]) {
+ *step = 2;
+ pat++;
+ esc = 1;
+ goto escaped;
+ }
+ if (pat[0]=='[') {
+ size_t k = 1;
+ if (k<m) if (pat[k] == '^' || pat[k] == '!') k++;
+ if (k<m) if (pat[k] == ']') k++;
+ for (; k<m && pat[k] && pat[k]!=']'; k++) {
+ if (k+1<m && pat[k+1] && pat[k]=='[' && (pat[k+1]==':' || pat[k+1]=='.' || pat[k+1]=='=')) {
+ int z = pat[k+1];
+ k+=2;
+ if (k<m && pat[k]) k++;
+ while (k<m && pat[k] && (pat[k-1]!=z || pat[k]!=']')) k++;
+ if (k==m || !pat[k]) break;
+ }
+ }
+ if (k==m || !pat[k]) {
+ *step = 1;
+ return '[';
+ }
+ *step = k+1;
+ return BRACKET;
+ }
+ if (pat[0] == '*')
+ return STAR;
+ if (pat[0] == '?')
+ return QUESTION;
+escaped:
+ if (pat[0] >= 128U) {
+ wchar_t wc;
+ int k = mbtowc(&wc, pat, m);
+ if (k<0) {
+ *step = 0;
+ return UNMATCHABLE;
+ }
+ *step = k + esc;
+ return wc;
+ }
+ return pat[0];
+}
+
+static int match_bracket(const char *p, int k, int kfold)
+{
+ wchar_t wc;
+ int inv = 0;
+ p++;
+ if (*p=='^' || *p=='!') {
+ inv = 1;
+ p++;
+ }
+ if (*p==']') {
+ if (k==']') return !inv;
+ p++;
+ } else if (*p=='-') {
+ if (k=='-') return !inv;
+ p++;
+ }
+ wc = p[-1];
+ for (; *p != ']'; p++) {
+ if (p[0]=='-' && p[1]!=']') {
+ wchar_t wc2;
+ int l = mbtowc(&wc2, p+1, 4);
+ if (l < 0) return 0;
+ if (wc <= wc2)
+ if ((unsigned)k-wc <= wc2-wc ||
+ (unsigned)kfold-wc <= wc2-wc)
+ return !inv;
+ p += l-1;
+ continue;
+ }
+ if (p[0]=='[' && (p[1]==':' || p[1]=='.' || p[1]=='=')) {
+ const char *p0 = p+2;
+ int z = p[1];
+ p+=3;
+ while (p[-1]!=z || p[0]!=']') p++;
+ if (z == ':' && p-1-p0 < 16) {
+ char buf[16];
+ memcpy(buf, p0, p-1-p0);
+ buf[p-1-p0] = 0;
+ if (iswctype(k, wctype(buf)) ||
+ iswctype(kfold, wctype(buf)))
+ return !inv;
+ }
+ continue;
+ }
+ if (*p < 128U) {
+ wc = (unsigned char)*p;
+ } else {
+ int l = mbtowc(&wc, p, 4);
+ if (l < 0) return 0;
+ p += l-1;
+ }
+ if (wc==k || wc==kfold) return !inv;
+ }
+ return inv;
+}
+
+static int fnmatch_internal(const char *pat, size_t m, const char *str, size_t n)
+{
+ const char *p, *ptail, *endpat;
+ const char *s, *stail, *endstr;
+ size_t pinc, sinc, tailcnt=0;
+ int c, k, kfold;
+
+ for (;;) {
+ switch ((c = pat_next(pat, m, &pinc))) {
+ case UNMATCHABLE:
+ return FNM_NOMATCH;
+ case STAR:
+ pat++;
+ m--;
+ break;
+ default:
+ k = str_next(str, n, &sinc);
+ if (k <= 0)
+ return (c==END) ? 0 : FNM_NOMATCH;
+ str += sinc;
+ n -= sinc;
+ kfold = k;
+ if (c == BRACKET) {
+ if (!match_bracket(pat, k, kfold))
+ return FNM_NOMATCH;
+ } else if (c != QUESTION && k != c && kfold != c) {
+ return FNM_NOMATCH;
+ }
+ pat+=pinc;
+ m-=pinc;
+ continue;
+ }
+ break;
+ }
+
+ /* Compute real pat length if it was initially unknown/-1 */
+ m = strnlen(pat, m);
+ endpat = pat + m;
+
+ /* Find the last * in pat and count chars needed after it */
+ for (p=ptail=pat; p<endpat; p+=pinc) {
+ switch (pat_next(p, endpat-p, &pinc)) {
+ case UNMATCHABLE:
+ return FNM_NOMATCH;
+ case STAR:
+ tailcnt=0;
+ ptail = p+1;
+ break;
+ default:
+ tailcnt++;
+ break;
+ }
+ }
+
+ /* Past this point we need not check for UNMATCHABLE in pat,
+ * because all of pat has already been parsed once. */
+
+ /* Compute real str length if it was initially unknown/-1 */
+ n = strnlen(str, n);
+ endstr = str + n;
+ if (n < tailcnt) return FNM_NOMATCH;
+
+ /* Find the final tailcnt chars of str, accounting for UTF-8.
+ * On illegal sequences we may get it wrong, but in that case
+ * we necessarily have a matching failure anyway. */
+ for (s=endstr; s>str && tailcnt; tailcnt--) {
+ if (s[-1] < 128U || MB_CUR_MAX==1) s--;
+ else while ((unsigned char)*--s-0x80U<0x40 && s>str);
+ }
+ if (tailcnt) return FNM_NOMATCH;
+ stail = s;
+
+ /* Check that the pat and str tails match */
+ p = ptail;
+ for (;;) {
+ c = pat_next(p, endpat-p, &pinc);
+ p += pinc;
+ if ((k = str_next(s, endstr-s, &sinc)) <= 0) {
+ if (c != END) return FNM_NOMATCH;
+ break;
+ }
+ s += sinc;
+ kfold = k;
+ if (c == BRACKET) {
+ if (!match_bracket(p-pinc, k, kfold))
+ return FNM_NOMATCH;
+ } else if (c != QUESTION && k != c && kfold != c) {
+ return FNM_NOMATCH;
+ }
+ }
+
+ /* We're all done with the tails now, so throw them out */
+ endstr = stail;
+ endpat = ptail;
+
+ /* Match pattern components until there are none left */
+ while (pat<endpat) {
+ p = pat;
+ s = str;
+ for (;;) {
+ c = pat_next(p, endpat-p, &pinc);
+ p += pinc;
+ /* Encountering * completes/commits a component */
+ if (c == STAR) {
+ pat = p;
+ str = s;
+ break;
+ }
+ k = str_next(s, endstr-s, &sinc);
+ if (!k)
+ return FNM_NOMATCH;
+ kfold = k;
+ if (c == BRACKET) {
+ if (!match_bracket(p-pinc, k, kfold))
+ break;
+ } else if (c != QUESTION && k != c && kfold != c) {
+ break;
+ }
+ s += sinc;
+ }
+ if (c == STAR) continue;
+ /* If we failed, advance str, by 1 char if it's a valid
+ * char, or past all invalid bytes otherwise. */
+ k = str_next(str, endstr-str, &sinc);
+ if (k > 0) str += sinc;
+ else for (str++; str_next(str, endstr-str, &sinc)<0; str++);
+ }
+
+ return 0;
+}
+
+int fnmatch(const char *pat, const char *str, int flags)
+{
+ const char *s, *p;
+ size_t inc;
+ int c;
+ if (flags & FNM_PATHNAME) for (;;) {
+ for (s=str; *s && *s!='/'; s++);
+ for (p=pat; (c=pat_next(p, -1, &inc))!=END && c!='/'; p+=inc);
+ if (c!=*s)
+ return FNM_NOMATCH;
+ if (fnmatch_internal(pat, p-pat, str, s-str))
+ return FNM_NOMATCH;
+ if (!c) return 0;
+ str = s+1;
+ pat = p+inc;
+ }
+ return fnmatch_internal(pat, -1, str, -1);
+}
+#endif /* HAVE_FNMATCH */
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