1 files changed, 119 insertions, 0 deletions
diff --git a/src/shared/compare-operator.c b/src/shared/compare-operator.c
new file mode 100644
index 0000000..ad931b7
--- /dev/null
+++ b/src/shared/compare-operator.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <fnmatch.h>
+
+#include "compare-operator.h"
+#include "string-util.h"
+
+CompareOperator parse_compare_operator(const char **s, CompareOperatorParseFlags flags) {
+        static const struct {
+                CompareOperator op;
+                const char *str;
+                CompareOperatorParseFlags valid_mask; /* If this operator appears when flags in mask not set, fail */
+                CompareOperatorParseFlags need_mask;  /* Skip over this operattor when flags in mask not set */
+        } table[] = {
+                { COMPARE_FNMATCH_EQUAL,    "$=",  .valid_mask = COMPARE_ALLOW_FNMATCH   },
+                { COMPARE_FNMATCH_UNEQUAL,  "!$=", .valid_mask = COMPARE_ALLOW_FNMATCH   },
+
+                { COMPARE_UNEQUAL,          "<>"                                         },
+                { COMPARE_LOWER_OR_EQUAL,   "<="                                         },
+                { COMPARE_GREATER_OR_EQUAL, ">="                                         },
+                { COMPARE_LOWER,            "<"                                          },
+                { COMPARE_GREATER,          ">"                                          },
+                { COMPARE_EQUAL,            "=="                                         },
+                { COMPARE_STRING_EQUAL,     "=",   .need_mask = COMPARE_EQUAL_BY_STRING  },
+                { COMPARE_EQUAL,            "="                                          },
+                { COMPARE_STRING_UNEQUAL,   "!=",  .need_mask = COMPARE_EQUAL_BY_STRING  },
+                { COMPARE_UNEQUAL,          "!="                                         },
+
+                { COMPARE_LOWER,            "lt",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+                { COMPARE_LOWER_OR_EQUAL,   "le",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+                { COMPARE_EQUAL,            "eq",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+                { COMPARE_UNEQUAL,          "ne",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+                { COMPARE_GREATER_OR_EQUAL, "ge",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+                { COMPARE_GREATER,          "gt",  .valid_mask = COMPARE_ALLOW_TEXTUAL   },
+        };
+
+        assert(s);
+
+        if (!*s) /* Hmm, we already reached the end, for example because extract_first_word() and
+                  * parse_compare_operator() are use on the same string? */
+                return _COMPARE_OPERATOR_INVALID;
+
+        for (size_t i = 0; i < ELEMENTSOF(table); i ++) {
+                const char *e;
+
+                if (table[i].need_mask != 0 && !FLAGS_SET(flags, table[i].need_mask))
+                        continue;
+
+                e = startswith(*s, table[i].str);
+                if (e) {
+                        if (table[i].valid_mask != 0 && !FLAGS_SET(flags, table[i].valid_mask))
+                                return _COMPARE_OPERATOR_INVALID;
+
+                        *s = e;
+                        return table[i].op;
+                }
+        }
+
+        return _COMPARE_OPERATOR_INVALID;
+}
+
+int test_order(int k, CompareOperator op) {
+
+        switch (op) {
+
+        case COMPARE_LOWER:
+                return k < 0;
+
+        case COMPARE_LOWER_OR_EQUAL:
+                return k <= 0;
+
+        case COMPARE_EQUAL:
+                return k == 0;
+
+        case COMPARE_UNEQUAL:
+                return k != 0;
+
+        case COMPARE_GREATER_OR_EQUAL:
+                return k >= 0;
+
+        case COMPARE_GREATER:
+                return k > 0;
+
+        default:
+                return -EINVAL;
+        }
+}
+
+int version_or_fnmatch_compare(
+                CompareOperator op,
+                const char *a,
+                const char *b) {
+        int r;
+
+        switch (op) {
+
+        case COMPARE_STRING_EQUAL:
+                return streq_ptr(a, b);
+
+        case COMPARE_STRING_UNEQUAL:
+                return !streq_ptr(a, b);
+
+        case COMPARE_FNMATCH_EQUAL:
+                r = fnmatch(b, a, 0);
+                return r == 0 ? true :
+                        r == FNM_NOMATCH ? false : -EINVAL;
+
+        case COMPARE_FNMATCH_UNEQUAL:
+                r = fnmatch(b, a, 0);
+                return r == FNM_NOMATCH ? true:
+                        r == 0 ? false : -EINVAL;
+
+        case _COMPARE_OPERATOR_ORDER_FIRST..._COMPARE_OPERATOR_ORDER_LAST:
+                return test_order(strverscmp_improved(a, b), op);
+
+        default:
+                return -EINVAL;
+        }
+}