[PATCH 0/1] MR6574: findstr: Support search with regular expressions.

[Hans Leidekker (＠hans)]

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6574

[PATCH 1/1] findstr: Support search with regular expressions.

[Hans Leidekker]

From: Hans Leidekker <hans(a)codeweavers.com>

---
 programs/findstr/main.c          | 64 +++++++++++++++++++++++++++++---
 programs/findstr/tests/findstr.c | 37 ++++++++++++++++++
 2 files changed, 95 insertions(+), 6 deletions(-)

diff --git a/programs/findstr/main.c b/programs/findstr/main.c
index f8f2de594c5..3e493bb3c71 100644
--- a/programs/findstr/main.c
+++ b/programs/findstr/main.c
@@ -97,9 +97,9 @@ static void add_string(struct findstr_string **head, const WCHAR *string)
     *ptr = new_string;
 }
 
-static const WCHAR *substring(const WCHAR *str, const WCHAR *substr, BOOL case_sensitive)
+static BOOL match_substring(const WCHAR *str, const WCHAR *substr, BOOL case_sensitive)
 {
-    if (case_sensitive) return wcsstr(str, substr);
+    if (case_sensitive) return !!wcsstr(str, substr);
 
     while (*str)
     {
@@ -110,11 +110,53 @@ static const WCHAR *substring(const WCHAR *str, const WCHAR *substr, BOOL case_s
             p1++;
             p2++;
         }
-        if (!*p2) return str;
+        if (!*p2) return TRUE;
         str++;
     }
 
-    return NULL;
+    return FALSE;
+}
+
+static inline BOOL is_op(WCHAR c, const WCHAR *regexp, UINT pos)
+{
+    if (!pos) return (*regexp == c);
+    return (regexp[pos] == c && regexp[pos - 1] != '\\');
+}
+
+static inline BOOL match_char(WCHAR c1, WCHAR c2, BOOL case_sensitive)
+{
+    if (case_sensitive) return c1 == c2;
+    return towlower(c1) == towlower(c2);
+}
+
+static BOOL match_star(WCHAR, const WCHAR *, const WCHAR *, UINT, BOOL);
+
+static BOOL match_here(const WCHAR *str, const WCHAR *regexp, UINT pos, BOOL case_sensitive)
+{
+    if (regexp[pos] == '\\' && regexp[pos + 1]) pos++;
+    if (!regexp[pos]) return TRUE;
+    if (is_op('*', regexp, pos + 1)) return match_star(regexp[pos], str, regexp, pos + 2, case_sensitive);
+    if (is_op('$', regexp, pos) && !regexp[pos + 1]) return (*str == '\n');
+    if (*str && (is_op('.', regexp, pos) || match_char(*str, regexp[pos], case_sensitive)))
+        return match_here(str + 1, regexp, pos + 1, case_sensitive);
+    return FALSE;
+}
+
+static BOOL match_star(WCHAR c, const WCHAR *str, const WCHAR *regexp, UINT pos, BOOL case_sensitive)
+{
+    do { if (match_here(str, regexp, pos, case_sensitive)) return TRUE; }
+    while (*str && (match_char(*str++, c, case_sensitive) || c == '.'));
+    return FALSE;
+}
+
+static BOOL match_regexp(const WCHAR *str, const WCHAR *regexp, BOOL case_sensitive)
+{
+    if (wcsstr(regexp, L"[")) FIXME("character ranges (i.e. [abc], [^a-z]) are not supported\n");
+    if (wcsstr(regexp, L"\\<") || wcsstr(regexp, L"\\>")) FIXME("word position (i.e. \\< and \\>) not supported\n");
+
+    if (regexp[0] == '^') return match_here(str, regexp, 1, case_sensitive);
+    do { if (match_here(str, regexp, 0, case_sensitive)) return TRUE; } while (*str++);
+    return FALSE;
 }
 
 int __cdecl wmain(int argc, WCHAR *argv[])
@@ -122,7 +164,7 @@ int __cdecl wmain(int argc, WCHAR *argv[])
     struct findstr_string *string_head = NULL, *current_string, *next_string;
     struct findstr_file *file_head = NULL, *current_file, *next_file;
     WCHAR *string, *ptr, *buffer, line[MAXSTRING];
-    BOOL has_string = FALSE, has_file = FALSE, case_sensitive = TRUE;
+    BOOL has_string = FALSE, has_file = FALSE, case_sensitive = TRUE, regular_expression = FALSE;
     int ret = 1, i, j;
 
     for (i = 0; i < argc; i++)
@@ -175,6 +217,10 @@ int __cdecl wmain(int argc, WCHAR *argv[])
                 case 'i':
                     case_sensitive = FALSE;
                     break;
+                case 'R':
+                case 'r':
+                    regular_expression = TRUE;
+                    break;
                 default:
                     findstr_error_wprintf(STRING_IGNORED, argv[i][j]);
                     break;
@@ -220,7 +266,13 @@ int __cdecl wmain(int argc, WCHAR *argv[])
             current_string = string_head;
             while (current_string)
             {
-                if (substring(line, current_string->string, case_sensitive))
+                BOOL match;
+
+                if (regular_expression)
+                    match = match_regexp(line, current_string->string, case_sensitive);
+                else
+                    match = match_substring(line, current_string->string, case_sensitive);
+                if (match)
                 {
                     wprintf(line);
                     if (current_file->file == stdin)
diff --git a/programs/findstr/tests/findstr.c b/programs/findstr/tests/findstr.c
index 3ededf7551b..9a30611fe8b 100644
--- a/programs/findstr/tests/findstr.c
+++ b/programs/findstr/tests/findstr.c
@@ -201,6 +201,43 @@ static void test_basic(void)
     ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
     ret = strcmp(stdout_buffer, "abc");
     ok(!ret, "Got the wrong result.\n");
+
+    /* find string in file, regular expression */
+    run_find_file("/R abc", "abc", 0);
+    ok(stdout_size > 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+    ret = strcmp(stdout_buffer, "abc");
+    ok(!ret, "Got the wrong result.\n");
+
+    /* find string in file with /C:, regular expression */
+    run_find_file("/R /C:^abc", "abc", 0);
+    ok(stdout_size > 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+    ret = strcmp(stdout_buffer, "abc");
+    ok(!ret, "Got the wrong result.\n");
+
+    /* find string in file, regular expression, case insensitive */
+    run_find_file("/I /R /C:.Bc", "abc", 0);
+    ok(stdout_size > 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+    ret = strcmp(stdout_buffer, "abc");
+    ok(!ret, "Got the wrong result.\n");
+
+    /* find string in file, regular expression, escape */
+    run_find_file("/R /C:\\.bc", "abc", 1);
+    ok(stdout_size == 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+
+    /* $ doesn't match if there's no newline */
+    run_find_file("/R /C:abc$", "abc", 1);
+    ok(stdout_size == 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+
+    run_find_file("/R /C:abc$", "abc\r\n", 0);
+    ok(stdout_size > 0, "Unexpected stdout buffer size %ld.\n", stdout_size);
+    ok(stderr_size == 0, "Unexpected stderr buffer size %ld.\n", stderr_size);
+    ret = strcmp(stdout_buffer, "abc\r\n");
+    ok(!ret, "Got the wrong result. '%s'\n", stdout_buffer);
 }
 
 START_TEST(findstr)
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/6574

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about programs/findstr/main.c:
> +    return (regexp[pos] == c && regexp[pos - 1] != '\\');
> +}
> +
> +static inline BOOL match_char(WCHAR c1, WCHAR c2, BOOL case_sensitive)
> +{
> +    if (case_sensitive) return c1 == c2;
> +    return towlower(c1) == towlower(c2);
> +}
> +
> +static BOOL match_star(WCHAR, const WCHAR *, const WCHAR *, UINT, BOOL);
> +
> +static BOOL match_here(const WCHAR *str, const WCHAR *regexp, UINT pos, BOOL case_sensitive)
> +{
> +    if (regexp[pos] == '\\' && regexp[pos + 1]) pos++;
> +    if (!regexp[pos]) return TRUE;
> +    if (is_op('*', regexp, pos + 1)) return match_star(regexp[pos], str, regexp, pos + 2, case_sensitive);
> `match_star` doesn't account for escaped dot. `FINDSTR /R /C:"\.*"` will therefore match anything (works like `.*`), not just a sequence of dots (e.g., `....`).

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6574#note_83552

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about programs/findstr/main.c:
> +        return match_here(str + 1, regexp, pos + 1, case_sensitive);
> +    return FALSE;
> +}
> +
> +static BOOL match_star(WCHAR c, const WCHAR *str, const WCHAR *regexp, UINT pos, BOOL case_sensitive)
> +{
> +    do { if (match_here(str, regexp, pos, case_sensitive)) return TRUE; }
> +    while (*str && (match_char(*str++, c, case_sensitive) || c == '.'));
> +    return FALSE;
> +}
> +
> +static BOOL match_regexp(const WCHAR *str, const WCHAR *regexp, BOOL case_sensitive)
> +{
> +    if (wcsstr(regexp, L"[")) FIXME("character ranges (i.e. [abc], [^a-z]) are not supported\n");
> +    if (wcsstr(regexp, L"\\<") || wcsstr(regexp, L"\\>")) FIXME("word position (i.e. \\< and \\>) not supported\n");
> +
    if (wcsstr(regexp + 1, L"^")) FIXME("metacharacter '^' found after first char\n");
    If (wcscspn(regexp, L"$") + 1 &lt; wcslen(regexp)) FIXME("metacharacter '$' found before last char\n");

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6574#note_83556