added GG_GIT_ALL behavior

README.md

@@ -26,13 +26,17 @@ It is intentionally narrow:
   skipped. A literal match that occurs *before* the first NUL in an
   otherwise-text file is still reported.
 - **Recursive by default.** Given a directory it walks the whole tree.
+- **Git-aware by default.** When walking a tree, `gg` honours every `.gitignore`
+  it encounters and always skips `.git` directories — just like `git` and `rg`.
+  Set `GG_GIT_ALL=1` to search everything instead (equivalent to `rg
+  --no-ignore`).
 - **Self-contained.** No third-party libraries, no shelling out to other
   programs. Just `libc` + `libpthread`.
 
 `gg` was built to be a clean, readable reference implementation that is also
 fast: on a 16 GB / ~209 000-file tree it completes the equivalent of
 `rg --no-ignore --hidden -l` in roughly **0.4 s**, about **1.5× faster than
-`rg`** on the same machine and query, using only portable POSIX interfaces.
+`rg`** on the same machine and query, using only portable POSIX interfaces. (With `GG_GIT_ALL` unset, the equivalent is `rg --hidden -l`.)
 
 ## Installation
 
@@ -113,8 +117,10 @@ gg "def main" src/main.py
 
 - **Symlinks are not followed.** Symbolic links to files or directories are
   skipped, which prevents infinite loops on symlink cycles.
-- **Hidden files and directories are searched.** Unlike `rg`'s default, `gg`
-  does not consult `.gitignore` or skip hidden paths.
+- **Hidden files and directories are searched.** `gg` does not skip hidden
+  paths. It *does* consult `.gitignore` files and skips `.git` directories by
+  default; set `GG_GIT_ALL=1` to disable that and search everything (including
+  ignored and `.git` paths).
 - **Binary files are skipped.** A file containing a NUL byte is never reported,
   even if it also contains the search term (except when the match occurs before
   the first NUL, in which case it is reported — see FAQ).
@@ -214,8 +220,20 @@ against symlink cycles and avoids double-counting.
 
 ### Does it respect `.gitignore`?
 
-No. `gg` searches everything it can read, including hidden files and directories.
-This is why its results match `rg --no-ignore --hidden`.
+Yes, by default. `gg` reads every `.gitignore` found while walking and skips
+matching files and directories, and it always skips `.git` directories — the
+same rules `git` itself uses (including `!` negation, `**` globs, and
+trailing-`/` directory-only patterns). Hidden files and directories are still
+searched; only `.gitignore`-matched paths and `.git` are excluded.
+
+To search everything — ignored files, `.git`, the lot — set the `GG_GIT_ALL`
+environment variable (to any value) before running `gg`:
+
+```sh
+GG_GIT_ALL=1 gg "needle" .
+```
+
+With `GG_GIT_ALL` set, `gg`'s results match `rg --no-ignore --hidden`.
 
 ### Why not `mmap` the files?
 

gg.c

@@ -4,6 +4,7 @@
  * Usage: gg SEARCH_TERM [FILE_OR_DIRECTORY]
  *
  * Created by Luxferre in 2026, released into the public domain
+ *
  */
 #ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200809L
@@ -15,6 +16,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <fnmatch.h>
 #include <pthread.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -34,16 +36,39 @@ static const char *needle;
 static size_t needle_len;
 static int found_any = 0;
 static pthread_mutex_t found_mx = PTHREAD_MUTEX_INITIALIZER;
+static int git_all = 0; /* if set, ignore .gitignore / .git entirely */
+
+/* ---------- .gitignore handling ---------- */
+typedef struct Pattern {
+  int negate;     /* pattern began with '!' */
+  int dir_only;   /* pattern ended with '/' (matches dirs only) */
+  int has_slash;  /* pattern contains a '/' (anchored to its .gitignore dir) */
+  char *pat;      /* pattern text (without '!' / trailing '/') */
+  size_t pat_len;
+} Pattern;
+
+typedef struct GitIgnore {
+  Pattern *pats;
+  size_t npats;
+  const char *rel;       /* directory this ignore governs, relative to root */
+  struct GitIgnore *parent;
+  struct GitIgnore *gnext; /* global list, for cleanup */
+} GitIgnore;
+
+static GitIgnore *gi_all = NULL;
+
 /* ---------- directory work queue (parallel walk + scan) ---------- */
 typedef struct DirJob {
-  char *path;
+  char *path; /* full path for opendir/open */
+  char *rel;  /* path relative to the search root ("" for root) */
+  GitIgnore *gi; /* active ignore set for this directory's children */
   struct DirJob *next;
 } DirJob;
 
 static DirJob *dir_stack = NULL;
 static pthread_mutex_t dir_mx = PTHREAD_MUTEX_INITIALIZER;
 
-static void push_dir(const char *path) {
+static void push_dir(const char *path, const char *rel, GitIgnore *gi) {
   DirJob *j = malloc(sizeof *j);
   if(j == NULL)
     return;
@@ -52,6 +77,13 @@ static void push_dir(const char *path) {
     free(j);
     return;
   }
+  j->rel = strdup(rel);
+  if(j->rel == NULL) {
+    free(j->path);
+    free(j);
+    return;
+  }
+  j->gi = gi;
   pthread_mutex_lock(&dir_mx);
   j->next = dir_stack;
   dir_stack = j;
@@ -63,17 +95,283 @@ static void die(const char *msg) {
   exit(2);
 }
 
-static char *pop_dir(void) {
+static void pop_dir(char **path, char **rel, GitIgnore **gi) {
   pthread_mutex_lock(&dir_mx);
   DirJob *j = dir_stack;
   if(j != NULL)
     dir_stack = j->next;
   pthread_mutex_unlock(&dir_mx);
-  if(j == NULL)
-    return NULL;
-  char *p = j->path;
+  if(j == NULL) {
+    *path = NULL;
+    *rel = NULL;
+    *gi = NULL;
+    return;
+  }
+  *path = j->path;
+  *rel = j->rel;
+  *gi = j->gi;
   free(j);
-  return p;
+}
+
+/* Read an entire fd into a malloc'd, NUL-terminated buffer. Returns the buffer
+ * (caller frees) and stores the length in *len, or NULL on error. */
+static char *read_all(int fd, size_t *len) {
+  size_t cap = 4096, n = 0;
+  char *buf = malloc(cap);
+  if(buf == NULL)
+    return NULL;
+  for(;;) {
+    if(n == cap) {
+      cap *= 2;
+      char *nb = realloc(buf, cap);
+      if(nb == NULL) {
+        free(buf);
+        return NULL;
+      }
+      buf = nb;
+    }
+    ssize_t r = read(fd, buf + n, cap - n);
+    if(r < 0) {
+      if(errno == EINTR)
+        continue;
+      free(buf);
+      return NULL;
+    }
+    if(r == 0)
+      break;
+    n += (size_t)r;
+  }
+  buf = realloc(buf, n + 1);
+  if(buf == NULL)
+    return NULL;
+  buf[n] = '\0';
+  *len = n;
+  return buf;
+}
+
+/* Parse a .gitignore buffer into patterns, chained under `parent`. Returns the
+ * new GitIgnore node (sharing `parent` if the file is empty/absent). */
+static GitIgnore *load_gitignore(const char *dir, GitIgnore *parent,
+                                 const char *rel) {
+  char path[PATH_MAX];
+  int n = snprintf(path, sizeof path, "%s/.gitignore", dir);
+  if(n < 0 || (size_t)n >= sizeof path)
+    return parent;
+  int fd = open(path, O_RDONLY | O_CLOEXEC);
+  if(fd < 0)
+    return parent;
+
+  size_t len = 0;
+  char *buf = read_all(fd, &len);
+  close(fd);
+  if(buf == NULL)
+    return parent;
+
+  Pattern *pa = NULL;
+  size_t np = 0, cap = 0;
+  char *p = buf, *end = buf + len;
+  while(p < end) {
+    char *nl = memchr(p, '\n', (size_t)(end - p));
+    size_t llen = (nl != NULL) ? (size_t)(nl - p) : (size_t)(end - p);
+    if(llen > 0 && p[llen - 1] == '\r')
+      llen--;
+    size_t s = 0;
+    while(s < llen && (p[s] == ' ' || p[s] == '\t'))
+      s++;
+    size_t e = llen;
+    while(e > s && (p[e - 1] == ' ' || p[e - 1] == '\t'))
+      e--;
+    if(s >= e || p[s] == '#') {
+      p = (nl != NULL) ? nl + 1 : end;
+      continue;
+    }
+    char *t = malloc(e - s + 1);
+    if(t == NULL)
+      break;
+    memcpy(t, p + s, e - s);
+    t[e - s] = '\0';
+
+    int negate = 0, dir_only = 0;
+    if(t[0] == '!') {
+      negate = 1;
+      memmove(t, t + 1, strlen(t));
+    }
+    size_t tl = strlen(t);
+    if(tl > 0 && t[tl - 1] == '/') {
+      dir_only = 1;
+      t[tl - 1] = '\0';
+      tl--;
+    }
+    int has_slash = (strchr(t, '/') != NULL);
+
+    if(np == cap) {
+      cap = cap ? cap * 2 : 16;
+      Pattern *na = realloc(pa, cap * sizeof *pa);
+      if(na == NULL) {
+        free(t);
+        break;
+      }
+      pa = na;
+    }
+    pa[np].negate = negate;
+    pa[np].dir_only = dir_only;
+    pa[np].has_slash = has_slash;
+    pa[np].pat = t;
+    pa[np].pat_len = tl;
+    np++;
+    p = (nl != NULL) ? nl + 1 : end;
+  }
+  free(buf);
+
+  if(np == 0) {
+    free(pa);
+    return parent;
+  }
+
+  GitIgnore *g = malloc(sizeof *g);
+  if(g == NULL) {
+    for(size_t i = 0; i < np; i++)
+      free(pa[i].pat);
+    free(pa);
+    return parent;
+  }
+  g->pats = pa;
+  g->npats = np;
+  g->rel = strdup(rel);
+  g->parent = parent;
+  g->gnext = gi_all;
+  gi_all = g;
+  return g;
+}
+
+/* Match a single path segment `s` (len sl) against a glob `p` (len pl) where
+ * '*' matches a run of non-'/' chars and '?' matches one char. */
+static int seg_eq(const char *p, size_t pl, const char *s, size_t sl) {
+  size_t i = 0, j = 0;
+  size_t star = SIZE_MAX, si = 0, sj = 0;
+  while(i < pl || j < sl) {
+    if(i < pl && p[i] == '*') {
+      star = i;
+      si = i + 1;
+      sj = j;
+      i++;
+      continue;
+    }
+    if(i < pl && (p[i] == '?' || (j < sl && p[i] == s[j]))) {
+      i++;
+      j++;
+      continue;
+    }
+    if(star != SIZE_MAX) {
+      /* Extend what the '*' matches by one more char of s, if possible. */
+      if(sj + 1 > sl)
+        break;
+      i = si;
+      sj++;
+      j = sj;
+      continue;
+    }
+    return 0;
+  }
+  return i == pl && j == sl;
+}
+
+/* Match a slash-separated pattern `p` against path `s`, supporting `**`. */
+static int match_path(const char *p, const char *s) {
+  for(;;) {
+    if(p[0] == '*' && p[1] == '*') {
+      p += 2;
+      while(*p == '/')
+        p++;
+      if(*p == '\0')
+        return 1;
+      const char *sp = s;
+      for(;;) {
+        if(match_path(p, sp))
+          return 1;
+        while(*sp && *sp != '/')
+          sp++;
+        if(*sp == '\0')
+          break;
+        sp++;
+      }
+      return 0;
+    }
+    if(*p == '\0')
+      return *s == '\0';
+    if(*p == '/') {
+      if(*s != '/')
+        return 0;
+      p++;
+      s++;
+      continue;
+    }
+    const char *pe = p;
+    while(*pe && *pe != '/')
+      pe++;
+    const char *se = s;
+    while(*se && *se != '/')
+      se++;
+    if(!seg_eq(p, (size_t)(pe - p), s, (size_t)(se - s)))
+      return 0;
+    p = pe;
+    s = se;
+  }
+}
+
+/* Match a gitignore pattern against a path (path relative to the owning
+ * .gitignore directory). A leading '/' only marks the pattern as anchored to
+ * that directory (it is already implied by `path`), so it is stripped before
+ * matching. Falls back to fnmatch for patterns without `**`. */
+static int git_match(const char *pat, const char *path) {
+  while(*pat == '/')
+    pat++;
+  if(*pat == '\0')
+    return *path == '\0';
+  if(strstr(pat, "**") == NULL)
+    return fnmatch(pat, path, FNM_PATHNAME) == 0;
+  return match_path(pat, path);
+}
+
+/* Decide whether an entry named `name` (full relative path `entry_rel`, a
+ * directory iff `is_dir`) is ignored by the active ignore set `gi`. The
+ * deepest matching rule wins (git semantics). */
+static int is_ignored(const char *entry_rel, const char *name, GitIgnore *gi,
+                      int is_dir) {
+  GitIgnore *chain[1024];
+  int n = 0;
+  for(GitIgnore *g = gi; g != NULL && n < 1024; g = g->parent)
+    chain[n++] = g;
+
+  int ignored = 0;
+  for(int i = n - 1; i >= 0; i--) { /* root -> child (deepest wins) */
+    GitIgnore *g = chain[i];
+    for(size_t p = 0; p < g->npats; p++) {
+      Pattern *pat = &g->pats[p];
+      int m;
+      if(pat->has_slash) {
+        const char *rp;
+        if(g->rel[0] == '\0') {
+          rp = entry_rel;
+        } else {
+          size_t rl = strlen(g->rel);
+          if(strncmp(entry_rel, g->rel, rl) != 0)
+            continue;
+          if(entry_rel[rl] != '/')
+            continue;
+          rp = entry_rel + rl + 1;
+        }
+        m = git_match(pat->pat, rp);
+      } else {
+        if(pat->dir_only && !is_dir)
+          continue;
+        m = git_match(pat->pat, name);
+      }
+      if(m)
+        ignored = pat->negate ? 0 : 1;
+    }
+  }
+  return ignored;
 }
 
 /* ---------- scan one open fd (chunked read + memmem, binary-skipping) ---------- */
@@ -154,10 +452,19 @@ static void *worker(void *arg) {
     return NULL;
   }
   char child[PATH_MAX];
+  char relbuf[PATH_MAX];
+
   for(;;) {
-    char *dir = pop_dir();
+    char *dir, *rel;
+    GitIgnore *parent_gi;
+    pop_dir(&dir, &rel, &parent_gi);
     if(dir == NULL)
       break;
+
+    GitIgnore *my_gi = parent_gi;
+    if(!git_all)
+      my_gi = load_gitignore(dir, parent_gi, rel);
+
     DIR *d = opendir(dir);
     if(d != NULL) {
       struct dirent *ent;
@@ -165,13 +472,35 @@ static void *worker(void *arg) {
         if(strcmp(ent->d_name, ".") == 0 ||
             strcmp(ent->d_name, "..") == 0)
           continue;
-        int n = snprintf(child, sizeof child, "%s/%s", dir, ent->d_name);
+        const char *name = ent->d_name;
+
+        int n = snprintf(child, sizeof child, "%s/%s", dir, name);
         if(n < 0 || (size_t)n >= sizeof child)
           continue;
+        n = snprintf(relbuf, sizeof relbuf, "%s%s%s",
+                     rel, (rel[0] == '\0') ? "" : "/", name);
+        if(n < 0 || (size_t)n >= sizeof relbuf)
+          continue;
+
+        int is_dir = (ent->d_type == DT_DIR);
+        if(ent->d_type == DT_UNKNOWN) {
+          struct stat st;
+          if(lstat(child, &st) == 0)
+            is_dir = S_ISDIR(st.st_mode);
+        }
+
+        if(!git_all) {
+          /* Always skip .git directories, just like git. */
+          if(strcmp(name, ".git") == 0 && is_dir)
+            continue;
+          if(is_ignored(relbuf, name, my_gi, is_dir))
+            continue;
+        }
+
         if(ent->d_type == DT_REG) {
           scan_file(child, &sb);
         } else if(ent->d_type == DT_DIR) {
-          push_dir(child);
+          push_dir(child, relbuf, my_gi);
         } else if(ent->d_type == DT_LNK) {
           continue; /* do not follow symlinks: avoids cycles */
         } else {
@@ -179,7 +508,7 @@ static void *worker(void *arg) {
           if(lstat(child, &st) != 0)
             continue;
           if(S_ISDIR(st.st_mode))
-            push_dir(child);
+            push_dir(child, relbuf, my_gi);
           else if(S_ISREG(st.st_mode))
             scan_file(child, &sb);
         }
@@ -187,12 +516,27 @@ static void *worker(void *arg) {
       closedir(d);
     }
     free(dir);
+    free(rel);
   }
   free(sb.buf);
   free(sb.carry);
   return NULL;
 }
 
+static void free_gitignores(void) {
+  GitIgnore *g = gi_all;
+  while(g != NULL) {
+    GitIgnore *next = g->gnext;
+    for(size_t i = 0; i < g->npats; i++)
+      free(g->pats[i].pat);
+    free(g->pats);
+    free((void *)g->rel);
+    free(g);
+    g = next;
+  }
+  gi_all = NULL;
+}
+
 int main(int argc, char **argv) {
   if(argc < 2 || argc > 3) {
     fprintf(stderr, "usage: %s SEARCH_TERM [FILE_OR_DIRECTORY]\n", argv[0]);
@@ -206,6 +550,8 @@ int main(int argc, char **argv) {
     return 2;
   }
 
+  git_all = (getenv("GG_GIT_ALL") != NULL);
+
   char cwd[PATH_MAX];
   const char *root;
   if(argc == 3) {
@@ -239,7 +585,7 @@ int main(int argc, char **argv) {
     scan_file(root, &(ScanBufs){ malloc(IO_BUFSZ + needle_len),
                                  malloc(needle_len) });
   } else {
-    push_dir(root);
+    push_dir(root, "", NULL);
   }
 
   long nproc = sysconf(_SC_NPROCESSORS_ONLN);
@@ -259,5 +605,6 @@ int main(int argc, char **argv) {
   for(int i = 0; i < started; i++)
     pthread_join(t[i], NULL);
 
+  free_gitignores();
   return found_any ? 0 : 1;
 }