Extend grep with -r, -v, -l, -w and -x flags

Adds the following options to grep based on maintainer feedback:

- `-r` / `-R` — recursive search through directories
- `-v` — invert match, print non-matching lines
- `-l` — print only filenames that contain matches
- `-w` — match whole words only
- `-x` — match whole lines only

Multi-file output is automatically prefixed with the filename.

src/userland/cli/grep.c

@@ -1,4 +1,4 @@
-// Copyright (c) 2023-2026 Chris (boreddevnl)
+// Copyright (c) 2026 maro (whitehai11)
 // This software is released under the GNU General Public License v3.0. See LICENSE file for details.
 // This header needs to maintain in any file it is present in, as per the GPL license terms.
 // BOREDOS_APP_DESC: Search for text inside a file.
@@ -10,6 +10,24 @@
 
 #define READ_BUF_SIZE 4096
 #define LINE_BUF_SIZE 1024
+#define MAX_PATH      512
+#define MAX_ENTRIES   256
+
+// Flags
+static int g_show_numbers  = 0;
+static int g_ignore_case   = 0;
+static int g_count_only    = 0;
+static int g_invert        = 0;  // -v
+static int g_files_only    = 0;  // -l
+static int g_word_match    = 0;  // -w
+static int g_line_match    = 0;  // -x
+static int g_recursive     = 0;  // -r / -R
+static int g_multi_file    = 0;  // more than one file → prefix output with filename
+
+static const char *g_pattern = NULL;
+
+// Total match count across all files (used for -c with -r)
+static int g_total_matches = 0;
 
 static int sc_strcmp(const char *a, const char *b) {
     while (*a && *a == *b) { a++; b++; }
@@ -17,14 +35,19 @@ static int sc_strcmp(const char *a, const char *b) {
 }
 
 static void print_usage(void) {
-    printf("Usage: grep [options] <text> <file>\n");
+    printf("Usage: grep [options] <pattern> <file> [file...]\n");
     printf("\n");
-    printf("Search for text inside a file.\n");
+    printf("Search for text inside files.\n");
     printf("\n");
     printf("Options:\n");
     printf("  -n      Show line numbers\n");
     printf("  -i      Case-insensitive search\n");
     printf("  -c      Print match count only\n");
+    printf("  -v      Invert match (print non-matching lines)\n");
+    printf("  -l      Print only filenames with matches\n");
+    printf("  -w      Match whole words only\n");
+    printf("  -x      Match whole lines only\n");
+    printf("  -r, -R  Recursive search in directories\n");
     printf("  -h      Show this help\n");
 }
 
@@ -33,6 +56,26 @@ static char to_lower(char c) {
     return c;
 }
 
+static int is_word_char(char c) {
+    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
+           (c >= '0' && c <= '9') || c == '_';
+}
+
+/* Check if needle appears in haystack at position i as a whole word */
+static int match_at(const char *haystack, int i, int h_len,
+                    const char *needle, int n_len, int ignore_case) {
+    for (int j = 0; j < n_len; j++) {
+        char h = ignore_case ? to_lower(haystack[i + j]) : haystack[i + j];
+        char n = ignore_case ? to_lower(needle[j])       : needle[j];
+        if (h != n) return 0;
+    }
+    if (g_word_match) {
+        if (i > 0 && is_word_char(haystack[i - 1])) return 0;
+        if (i + n_len < h_len && is_word_char(haystack[i + n_len])) return 0;
+    }
+    return 1;
+}
+
 static int str_contains(const char *haystack, const char *needle, int ignore_case) {
     int h_len = (int)strlen(haystack);
     int n_len = (int)strlen(needle);
@@ -41,31 +84,146 @@ static int str_contains(const char *haystack, const char *needle, int ignore_cas
     if (n_len > h_len) return 0;
 
     for (int i = 0; i <= h_len - n_len; i++) {
-        int match = 1;
+        if (match_at(haystack, i, h_len, needle, n_len, ignore_case))
-        for (int j = 0; j < n_len; j++) {
+            return 1;
-            char h = ignore_case ? to_lower(haystack[i + j]) : haystack[i + j];
-            char n = ignore_case ? to_lower(needle[j]) : needle[j];
-            if (h != n) { match = 0; break; }
-        }
-        if (match) return 1;
     }
     return 0;
 }
 
+static int line_matches(const char *line) {
+    if (g_line_match) {
+        /* Whole line must equal pattern */
+        int h_len = (int)strlen(line);
+        int n_len = (int)strlen(g_pattern);
+        if (h_len != n_len) return 0;
+        return match_at(line, 0, h_len, g_pattern, n_len, g_ignore_case);
+    }
+    return str_contains(line, g_pattern, g_ignore_case);
+}
+
+/* Grep a single open file descriptor, printing results prefixed by filename if needed */
+static int grep_fd(int fd, const char *filename) {
+    static char read_buf[READ_BUF_SIZE];
+    static char line[LINE_BUF_SIZE];
+    int line_pos  = 0;
+    int line_num  = 0;
+    int match_cnt = 0;
+
+    /* Helper: process one complete line */
+    #define PROCESS_LINE() do { \
+        line[line_pos] = '\0'; \
+        line_num++; \
+        int matched = line_matches(line); \
+        if (g_invert) matched = !matched; \
+        if (matched) { \
+            match_cnt++; \
+            if (!g_count_only && !g_files_only) { \
+                if (g_multi_file) printf("%s:", filename); \
+                if (g_show_numbers) printf("%d:", line_num); \
+                printf("%s\n", line); \
+            } \
+        } \
+        line_pos = 0; \
+    } while (0)
+
+    while (1) {
+        int bytes = sys_read(fd, read_buf, READ_BUF_SIZE);
+        if (bytes <= 0) break;
+
+        for (int i = 0; i < bytes; i++) {
+            char c = read_buf[i];
+            if (c == '\n' || line_pos >= LINE_BUF_SIZE - 1) {
+                PROCESS_LINE();
+            } else if (c != '\r') {
+                line[line_pos++] = c;
+            }
+        }
+    }
+    if (line_pos > 0) PROCESS_LINE();
+
+    #undef PROCESS_LINE
+
+    if (g_count_only)
+        printf("%s%d\n", g_multi_file ? filename : "", match_cnt > 0 ? match_cnt : 0);
+
+    if (g_files_only && match_cnt > 0)
+        printf("%s\n", filename);
+
+    g_total_matches += match_cnt;
+    return match_cnt;
+}
+
+static int grep_file(const char *path) {
+    int fd = sys_open(path, "r");
+    if (fd < 0) {
+        printf("grep: cannot open '%s'\n", path);
+        return 0;
+    }
+    int n = grep_fd(fd, path);
+    sys_close(fd);
+    return n;
+}
+
+static void grep_recursive(const char *path) {
+    FAT32_FileInfo info;
+    if (sys_get_file_info(path, &info) < 0) {
+        printf("grep: cannot access '%s'\n", path);
+        return;
+    }
+
+    if (!info.is_directory) {
+        grep_file(path);
+        return;
+    }
+
+    FAT32_FileInfo entries[MAX_ENTRIES];
+    int count = sys_list(path, entries, MAX_ENTRIES);
+    if (count < 0) return;
+
+    for (int i = 0; i < count; i++) {
+        const char *name = entries[i].name;
+        if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')))
+            continue;
+
+        char full[MAX_PATH];
+        int plen = (int)strlen(path);
+        int nlen = (int)strlen(name);
+        if (plen + 1 + nlen + 1 > MAX_PATH) continue;
+
+        int slash = (plen == 1 && path[0] == '/') ? 0 : 1;
+        for (int j = 0; j < plen; j++) full[j] = path[j];
+        if (slash) full[plen] = '/';
+        for (int j = 0; j <= nlen; j++) full[plen + slash + j] = name[j];
+
+        if (entries[i].is_directory)
+            grep_recursive(full);
+        else
+            grep_file(full);
+    }
+}
+
 int main(int argc, char **argv) {
-    int show_numbers = 0;
-    int ignore_case  = 0;
-    int count_only   = 0;
     int arg_offset = 1;
 
     for (int i = 1; i < argc; i++) {
         if (argv[i][0] != '-') break;
         if (sc_strcmp(argv[i], "-n") == 0) {
-            show_numbers = 1; arg_offset++;
+            g_show_numbers = 1; arg_offset++;
         } else if (sc_strcmp(argv[i], "-i") == 0) {
-            ignore_case = 1; arg_offset++;
+            g_ignore_case = 1; arg_offset++;
         } else if (sc_strcmp(argv[i], "-c") == 0) {
-            count_only = 1; arg_offset++;
+            g_count_only = 1; arg_offset++;
+        } else if (sc_strcmp(argv[i], "-v") == 0) {
+            g_invert = 1; arg_offset++;
+        } else if (sc_strcmp(argv[i], "-l") == 0) {
+            g_files_only = 1; arg_offset++;
+        } else if (sc_strcmp(argv[i], "-w") == 0) {
+            g_word_match = 1; arg_offset++;
+        } else if (sc_strcmp(argv[i], "-x") == 0) {
+            g_line_match = 1; arg_offset++;
+        } else if (sc_strcmp(argv[i], "-r") == 0 ||
+                   sc_strcmp(argv[i], "-R") == 0) {
+            g_recursive = 1; arg_offset++;
         } else if (sc_strcmp(argv[i], "-h") == 0 ||
                    sc_strcmp(argv[i], "--help") == 0) {
             print_usage();
@@ -76,73 +234,29 @@ int main(int argc, char **argv) {
         }
     }
 
+    if (argc - arg_offset < 1) {
+        print_usage();
+        return 1;
+    }
+
+    g_pattern = argv[arg_offset];
+
+    // Need at least a path when not reading stdin
     if (argc - arg_offset < 2) {
         print_usage();
         return 1;
     }
 
-    const char *pattern = argv[arg_offset];
+    // Multiple files → prefix output with filename
-    const char *path    = argv[arg_offset + 1];
+    g_multi_file = (argc - arg_offset > 2) || g_recursive;
 
-    int fd = sys_open(path, "r");
+    for (int i = arg_offset + 1; i < argc; i++) {
-    if (fd < 0) {
+        if (g_recursive) {
-        printf("grep: cannot open '%s'\n", path);
+            grep_recursive(argv[i]);
-        return 1;
+        } else {
-    }
+            grep_file(argv[i]);
-
-    static char read_buf[READ_BUF_SIZE];
-    static char line[LINE_BUF_SIZE];
-    int line_pos  = 0;
-    int line_num  = 0;
-    int match_cnt = 0;
-
-    while (1) {
-        int bytes = sys_read(fd, read_buf, READ_BUF_SIZE);
-        if (bytes <= 0) break;
-
-        for (int i = 0; i < bytes; i++) {
-            char c = read_buf[i];
-
-            if (c == '\n' || line_pos >= LINE_BUF_SIZE - 1) {
-                line[line_pos] = '\0';
-                line_num++;
-
-                if (str_contains(line, pattern, ignore_case)) {
-                    match_cnt++;
-                    if (!count_only) {
-                        if (show_numbers)
-                            printf("%d: %s\n", line_num, line);
-                        else
-                            printf("%s\n", line);
         }
     }
 
-                line_pos = 0;
+    return g_total_matches > 0 ? 0 : 1;
-            } else if (c != '\r') {
-                line[line_pos++] = c;
-            }
-        }
-    }
-
-    // Handle last line if file doesn't end with newline
-    if (line_pos > 0) {
-        line[line_pos] = '\0';
-        line_num++;
-        if (str_contains(line, pattern, ignore_case)) {
-            match_cnt++;
-            if (!count_only) {
-                if (show_numbers)
-                    printf("%d: %s\n", line_num, line);
-                else
-                    printf("%s\n", line);
-            }
-        }
-    }
-
-    sys_close(fd);
-
-    if (count_only)
-        printf("%d\n", match_cnt);
-
-    return match_cnt > 0 ? 0 : 1;
 }