glob

commit 7e3455639d25a44c0530feffd78a1365802f6da3
Author: Louis Burda <quent.burda@gmail.com>
Date:   Thu, 27 Jul 2023 08:23:08 +0200

Add initial prototype

Diffstat:
A
.gitignore
 | 
1
+
A
Makefile
 | 
17
+++++++++++++++++
A
glob.c
 | 
147
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 165 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1 @@
+glob
diff --git a/Makefile b/Makefile
@@ -0,0 +1,17 @@
+PREFIX ?= /usr/local
+BINDIR ?= /bin
+
+CFLAGS = -Wunused-variable -Wunused-function -Wconversion
+
+all: glob
+
+clean:
+	rm -f glob
+
+glob: glob.c
+
+install:
+	install -m755 glob -t "$(DESTDIR)$(PREFIX)$(BINDIR)"
+
+uninstall:
+	rm -f "$(DESTDIR)$(PREFIX)$(BINDIR)/glob"
diff --git a/glob.c b/glob.c
@@ -0,0 +1,147 @@
+#include <limits.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <linux/limits.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static char *
+esc_strchr(const char *esc, char c)
+{
+	const char *e;
+
+	for (e = esc; *e; e++) {
+		if (*e == '\\') e++;
+		else if (*e == c) return (char *) e;
+	}
+
+	return NULL;
+}
+
+static bool
+esc_strcmp(const char **esc, const char **str, const char *except)
+{
+	const char *e, *s;
+
+	for (e = *esc, s = *str; *s && *e; s++, e++) {
+		if (*e == '\\') e++;
+		else if (strchr(except, *e)) break;
+		if (*s != *e) return false;
+	}
+	*esc = e;
+	*str = s;
+
+	return (!*s && !*e) || strchr(except, *e);
+}
+
+static bool
+esc_strstr(const char **esc, const char **str, const char *except)
+{
+	for (; **str; (*str)++) {
+		if (esc_strcmp(esc, str, except))
+			return true;
+	}
+
+	return false;
+}
+
+static bool
+match(const char *pat, const char *str)
+{
+	const char *p;
+
+	p = pat;
+	while (1) {
+		if (p == pat) {
+			if (!esc_strcmp(&p, &str, "*/"))
+				return false;
+		} else {
+			if (!esc_strstr(&p, &str, "*/"))
+				return false;
+		}
+		if (*p == '/' || !*p)
+			break;
+		p += 1;
+	}
+
+	return true;
+}
+
+static void
+glob_r(int fd, char *buf, size_t off, size_t n, const char *pat)
+{
+	struct dirent *ent;
+	size_t len;
+	char *sep;
+	int sfd;
+	DIR *d;
+
+	d = fdopendir(fd);
+	if (!d) return;
+
+	sep = esc_strchr(pat, '/');
+	while ((ent = readdir(d))) {
+		if (!strcmp(ent->d_name, ".")) continue;
+		if (!strcmp(ent->d_name, "..")) continue;
+		if (match(pat, ent->d_name)) {
+			if (sep && ent->d_type == DT_DIR) {
+				sfd = openat(fd, ent->d_name, O_DIRECTORY);
+				if (sfd < 0) {
+					fprintf(stderr, "glob: openat '%s%s': %s\n",
+						buf, ent->d_name, strerror(errno));
+					continue;
+				}
+				len = strlen(ent->d_name);
+				if (len + 2 > n - off) {
+					fprintf(stderr, "glob: len > PATH_MAX\n");
+					exit(1);
+				}
+				strcpy(buf + off, ent->d_name);
+				strcpy(buf + off + len, "/");
+				glob_r(sfd, buf, off + len + 1, n, sep + 1);
+				close(sfd);
+			} else {
+				fputs(buf, stdout);
+				puts(ent->d_name);
+			}
+		}
+	}
+
+	closedir(d);
+}
+
+static void
+glob(const char *pat)
+{
+	char buf[PATH_MAX];
+	const char *dirname;
+	int fd;
+
+	buf[0] = '\0';
+	dirname = pat[0] == '/' ? "/" : ".";
+	fd = open(dirname, O_DIRECTORY);
+	if (fd < 0) {
+		fprintf(stderr, "glob: open '%s': %s\n",
+			dirname, strerror(errno));
+		exit(1);
+	}
+	glob_r(fd, buf, 0, PATH_MAX, pat);
+	close(fd);
+}
+
+int
+main(int argc, const char **argv)
+{
+	const char **arg;
+
+	if (!argc) return 1;
+
+	for (arg = argv + 1; *arg; arg++)
+		glob(*arg);
+}