lsfd: (filter) implement =~, an operator for regex matching

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/hardlink.c b/misc-utils/hardlink.c
index a275f2c4247093306ef6ba3db293da7659f12b97..88959caf0259969774f3196da03e3cc2314c6cee 100644 (file)
--- a/misc-utils/hardlink.c
+++ b/misc-utils/hardlink.c
@@ -44,7 +44,7 @@
 #include "monotonic.h"
 #include "optutils.h"
 
-#include <regex.h>             /* regcomp(), regsearch() */
+#include <regex.h>             /* regcomp(), regexec() */
 
 #ifdef HAVE_SYS_XATTR_H
 # include <sys/xattr.h>                /* listxattr, getxattr */

diff --git a/misc-utils/lsfd-filter.c b/misc-utils/lsfd-filter.c
index 468f8fce266cdc8c37af3692036fc3d43fb6f33e..7b525a61798a69ed5e277e56d1d0d0e30385daf9 100644 (file)
--- a/misc-utils/lsfd-filter.c
+++ b/misc-utils/lsfd-filter.c
@@ -16,6 +16,7 @@
 
 #include <string.h>
 #include <ctype.h>
+#include <regex.h>             /* regcomp(), regexec() */
 
 /*
  * Definitions
@@ -38,9 +39,7 @@ enum token_type {
        TOKEN_OPEN,             /* ( */
        TOKEN_CLOSE,            /* ) */
        TOKEN_OP1,              /* !, not */
-       TOKEN_OP2,              /* TODO: =~, !~ (regex match)
-                                *       =*, !* (glob match with fnmatch()
-                                */
+       TOKEN_OP2,              /* TODO: =*, !* (glob match with fnmatch() */
        TOKEN_EOF,
 };
 
@@ -57,6 +56,7 @@ enum op2_type {
        OP2_LE,
        OP2_GT,
        OP2_GE,
+       OP2_RE_MATCH,
 };
 
 struct token {
@@ -102,6 +102,7 @@ enum node_type {
        NODE_STR,
        NODE_NUM,
        NODE_BOOL,
+       NODE_RE,
        NODE_OP1,
        NODE_OP2,
 };
@@ -135,6 +136,7 @@ struct node_val {
                char *str;
                unsigned long long num;
                bool boolean;
+               regex_t re;
        } val;
 };
 
@@ -196,17 +198,22 @@ static bool op2_lt (struct node *, struct node *, struct parameter*, struct libs
 static bool op2_le (struct node *, struct node *, struct parameter*, struct libscols_line *);
 static bool op2_gt (struct node *, struct node *, struct parameter*, struct libscols_line *);
 static bool op2_ge (struct node *, struct node *, struct parameter*, struct libscols_line *);
+static bool op2_re_match (struct node *, struct node *, struct parameter*, struct libscols_line *);
+
 static bool op2_check_type_eq_or_bool_or_op(struct parser *, struct op2_class *, struct node *, struct node *);
 static bool op2_check_type_boolean_or_op   (struct parser *, struct op2_class *, struct node *, struct node *);
 static bool op2_check_type_num             (struct parser *, struct op2_class *, struct node *, struct node *);
+static bool op2_check_type_re              (struct parser *, struct op2_class *, struct node *, struct node *);
 
 static void node_str_free(struct node *);
+static void node_re_free (struct node *);
 static void node_op1_free(struct node *);
 static void node_op2_free(struct node *);
 
 static void node_str_dump (struct node *, struct parameter*, int, FILE *);
 static void node_num_dump (struct node *, struct parameter*, int, FILE *);
 static void node_bool_dump(struct node *, struct parameter*, int, FILE *);
+static void node_re_dump  (struct node *, struct parameter*, int, FILE *);
 static void node_op1_dump (struct node *, struct parameter*, int, FILE *);
 static void node_op2_dump (struct node *, struct parameter*, int, FILE *);
 
@@ -307,6 +314,11 @@ struct op2_class op2_classes [] = {
                .is_acceptable = op2_ge,
                .check_type = op2_check_type_num,
        },
+       [OP2_RE_MATCH] = {
+               .name = "=~",
+               .is_acceptable = op2_re_match,
+               .check_type = op2_check_type_re,
+       },
 };
 
 #define NODE_CLASS(NODE) (&node_classes[(NODE)->type])
@@ -324,6 +336,11 @@ struct node_class node_classes[] = {
                .name = "BOOL",
                .dump = node_bool_dump,
        },
+       [NODE_RE] = {
+               .name = "STR",
+               .free = node_re_free,
+               .dump = node_re_dump,
+       },
        [NODE_OP1]   = {
                .name = "OP1",
                .free = node_op1_free,
@@ -523,6 +540,10 @@ static struct token *parser_read(struct parser *parser)
                        t->type = TOKEN_OP2;
                        t->val.op2 = OP2_EQ;
                        break;
+               } else if (c0 == '~') {
+                       t->type = TOKEN_OP2;
+                       t->val.op2 = OP2_RE_MATCH;
+                       break;
                }
                snprintf(parser->errmsg, ERRMSG_LEN,
                         _("error: unexpected character %c after ="), c0);
@@ -979,6 +1000,12 @@ static void node_bool_dump(struct node *node, struct parameter* params, int dept
                        : token_classes[TOKEN_FALSE].name);
 }
 
+static void node_re_dump(struct node *node, struct parameter* params __attribute__((__unused__)),
+                        int depth __attribute__((__unused__)), FILE *stream)
+{
+       fprintf(stream, ": #<regexp %p>\n", &VAL(node,re));
+}
+
 static void node_op1_dump(struct node *node, struct parameter* params, int depth, FILE *stream)
 {
        fprintf(stream, ": %s\n", ((struct node_op1 *)node)->opclass->name);
@@ -998,6 +1025,11 @@ static void node_str_free(struct node *node)
                free(VAL(node,str));
 }
 
+static void node_re_free(struct node *node)
+{
+       regfree(&VAL(node,re));
+}
+
 static void node_op1_free(struct node *node)
 {
        node_free(((struct node_op1 *)node)->arg);
@@ -1120,6 +1152,15 @@ static bool op2_ge(struct node *left, struct node *right, struct parameter *para
        OP2_CMP_BODY(>=);
 }
 
+static bool op2_re_match(struct node *left, struct node *right,
+                        struct parameter *params, struct libscols_line *ln)
+{
+       const char *str;
+       OP2_GET_STR(left, str);
+
+       return (regexec(&VAL(right,re), str, 0, NULL, 0) == 0);
+}
+
 static bool op2_check_type_boolean_or_op(struct parser* parser, struct op2_class *op2_class,
                                         struct node *left, struct node *right)
 {
@@ -1177,6 +1218,52 @@ static bool op2_check_type_num(struct parser* parser, struct op2_class *op2_clas
        return true;
 }
 
+static bool op2_check_type_re(struct parser* parser, struct op2_class *op2_class,
+                             struct node *left, struct node *right)
+{
+       if (left->type != NODE_STR) {
+               snprintf(parser->errmsg, ERRMSG_LEN,
+                        _("error: unexpected left operand type %s for: %s"),
+                        NODE_CLASS(left)->name,
+                        op2_class->name);
+               return false;
+       }
+
+       if (right->type != NODE_STR) {
+               snprintf(parser->errmsg, ERRMSG_LEN,
+                        _("error: unexpected right operand type %s for: %s"),
+                        NODE_CLASS(right)->name,
+                        op2_class->name);
+               return false;
+       }
+       if (PINDEX(right) >= 0) {
+               snprintf(parser->errmsg, ERRMSG_LEN,
+                        _("error: string literal is expected as right operand for: %s"),
+                        op2_class->name);
+               return false;
+       }
+
+       char *regex = VAL(right, str);
+       VAL(right, str) = NULL;
+
+       int err = regcomp(&VAL(right, re), regex, REG_NOSUB | REG_EXTENDED);
+       if (err != 0) {
+               size_t size = regerror(err, &VAL(right, re), NULL, 0);
+               char *buf = xmalloc(size + 1);
+
+               regerror(err, &VAL(right, re), buf, size);
+
+               snprintf(parser->errmsg, ERRMSG_LEN,
+                        _("error: could not compile regular expression %s: %s"),
+                        regex, buf);
+               free(buf);
+               return false;
+       }
+       right->type = NODE_RE;
+       free(regex);
+       return true;
+}
+
 struct lsfd_filter *lsfd_filter_new(const char *const expr, struct libscols_table *tb,
                                      int ncols,
                                      int (*column_name_to_id)(const char *, void *),