Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame^] | 1 | /* |
| 2 | |
| 3 | match.c |
| 4 | |
| 5 | Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 6 | |
| 7 | Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | All rights reserved |
| 9 | |
| 10 | Created: Thu Jun 22 01:17:50 1995 ylo |
| 11 | |
| 12 | Simple pattern matching, with '*' and '?' as wildcards. |
| 13 | |
| 14 | */ |
| 15 | |
| 16 | #include "includes.h" |
| 17 | RCSID("$Id: match.c,v 1.1 1999/10/27 03:42:44 damien Exp $"); |
| 18 | |
| 19 | #include "ssh.h" |
| 20 | |
| 21 | /* Returns true if the given string matches the pattern (which may contain |
| 22 | ? and * as wildcards), and zero if it does not match. */ |
| 23 | |
| 24 | int match_pattern(const char *s, const char *pattern) |
| 25 | { |
| 26 | while (1) |
| 27 | { |
| 28 | /* If at end of pattern, accept if also at end of string. */ |
| 29 | if (!*pattern) |
| 30 | return !*s; |
| 31 | |
| 32 | /* Process '*'. */ |
| 33 | if (*pattern == '*') |
| 34 | { |
| 35 | /* Skip the asterisk. */ |
| 36 | pattern++; |
| 37 | |
| 38 | /* If at end of pattern, accept immediately. */ |
| 39 | if (!*pattern) |
| 40 | return 1; |
| 41 | |
| 42 | /* If next character in pattern is known, optimize. */ |
| 43 | if (*pattern != '?' && *pattern != '*') |
| 44 | { |
| 45 | /* Look instances of the next character in pattern, and try |
| 46 | to match starting from those. */ |
| 47 | for (; *s; s++) |
| 48 | if (*s == *pattern && |
| 49 | match_pattern(s + 1, pattern + 1)) |
| 50 | return 1; |
| 51 | /* Failed. */ |
| 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | /* Move ahead one character at a time and try to match at each |
| 56 | position. */ |
| 57 | for (; *s; s++) |
| 58 | if (match_pattern(s, pattern)) |
| 59 | return 1; |
| 60 | /* Failed. */ |
| 61 | return 0; |
| 62 | } |
| 63 | |
| 64 | /* There must be at least one more character in the string. If we are |
| 65 | at the end, fail. */ |
| 66 | if (!*s) |
| 67 | return 0; |
| 68 | |
| 69 | /* Check if the next character of the string is acceptable. */ |
| 70 | if (*pattern != '?' && *pattern != *s) |
| 71 | return 0; |
| 72 | |
| 73 | /* Move to the next character, both in string and in pattern. */ |
| 74 | s++; |
| 75 | pattern++; |
| 76 | } |
| 77 | /*NOTREACHED*/ |
| 78 | } |