lass init

1 files changed, 177 insertions, 0 deletions

diff --git a/src/lass.c b/src/lass.c
new file mode 100644
index 0000000..ddbced0
--- /dev/null
+++ b/src/lass.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * lass.c - list files and directories in kernel style
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <pwd.h>
+#include <grp.h>
+#include <time.h>
+#include <math.h>
+#include <limits.h>
+
+static int cmp_entries(const void *a, const void *b)
+{
+	const char *fa = *(const char **)a;
+	const char *fb = *(const char **)b;
+
+	return strcmp(fa, fb);
+}
+
+static void print_file_info(const char *path, const char *name, int width_uid,
+			   int width_gid, int width_size)
+{
+	struct stat st;
+	struct passwd *pw;
+	struct group *gr;
+	struct tm *timeinfo;
+	time_t rawtime;
+	char time_buffer[20];
+
+	if (stat(path, &st))
+		return;
+
+	printf(S_ISDIR(st.st_mode) ? "d" :
+	       S_ISSOCK(st.st_mode) ? "s" :
+	       S_ISREG(st.st_mode) ? "-" :
+	       S_ISLNK(st.st_mode) ? "l" :
+	       S_ISCHR(st.st_mode) ? "c" :
+	       S_ISBLK(st.st_mode) ? "b" :
+	       S_ISFIFO(st.st_mode) ? "p" : "?");
+
+	printf((st.st_mode & 0400) ? "r" : "-");
+	printf((st.st_mode & 0200) ? "w" : "-");
+	printf((st.st_mode & 0100) ? "x" : "-");
+	printf((st.st_mode & 0040) ? "r" : "-");
+	printf((st.st_mode & 0020) ? "w" : "-");
+	printf((st.st_mode & 0010) ? "x" : "-");
+	printf((st.st_mode & 0004) ? "r" : "-");
+	printf((st.st_mode & 0002) ? "w" : "-");
+	printf((st.st_mode & 0001) ? "x" : "-");
+
+	pw = getpwuid(st.st_uid);
+	gr = getgrgid(st.st_gid);
+
+	printf(" %*s %*s ", width_uid, pw ? pw->pw_name : "?",
+	       width_gid, gr ? gr->gr_name : "?");
+
+	time(&rawtime);
+	timeinfo = localtime(&rawtime);
+
+	strftime(time_buffer, sizeof(time_buffer),
+		"%a %b %d %H:%M:%S %Y", timeinfo);
+
+	printf("%s ", time_buffer);
+
+	if (S_ISSOCK(st.st_mode) || S_ISFIFO(st.st_mode))
+		printf("%*d ", width_size, 0);
+	else
+		printf("%*zu ", width_size, st.st_size);
+
+	printf("%s\n", name);
+}
+
+static int list_files(const char *path)
+{
+	DIR *dir;
+	struct dirent *entry;
+	char **entries;
+	size_t file_count;
+	size_t capacity;
+	int width_uid;
+	int width_gid;
+	int width_size;
+	int size_digits;
+	struct stat st;
+	struct passwd *pw;
+	struct group *gr;
+	char fullpath[PATH_MAX];
+
+	file_count = 0;
+	capacity = 2;
+	width_uid = 0;
+	width_gid = 0;
+	width_size = 0;
+
+	if (stat(path, &st))
+		return 1;
+
+	if (!S_ISDIR(st.st_mode)) {
+		pw = getpwuid(st.st_uid);
+		gr = getgrgid(st.st_gid);
+		width_uid = pw ? strlen(pw->pw_name) : 1;
+		width_gid = gr ? strlen(gr->gr_name) : 1;
+		width_size = (st.st_size == 0) ? 1 : (int)log10(st.st_size) + 1;
+		print_file_info(path, path, width_uid, width_gid, width_size);
+		return 0;
+	}
+
+	dir = opendir(path);
+	if (!dir)
+		return 1;
+
+	entries = malloc(capacity * sizeof(char *));
+	if (!entries) {
+		closedir(dir);
+		return 1;
+	}
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (file_count == capacity) {
+			capacity *= 2;
+			entries = realloc(entries, capacity * sizeof(char *));
+			if (!entries) {
+				closedir(dir);
+				return 1;
+			}
+		}
+		entries[file_count] = strdup(entry->d_name);
+		if (!entries[file_count])
+			continue;
+
+		snprintf(fullpath, sizeof(fullpath), "%s/%s", path,
+			 entry->d_name);
+		if (stat(fullpath, &st))
+			continue;
+
+		pw = getpwuid(st.st_uid);
+		gr = getgrgid(st.st_gid);
+
+		size_digits = (st.st_size == 0) ? 1 : (int)log10(st.st_size)+1;
+
+		if (size_digits > width_size)
+			width_size = size_digits;
+		if (pw && (int)strlen(pw->pw_name) > width_uid)
+			width_uid = strlen(pw->pw_name);
+		if (gr && (int)strlen(gr->gr_name) > width_gid)
+			width_gid = strlen(gr->gr_name);
+
+		file_count++;
+	}
+
+	closedir(dir);
+
+	qsort(entries, file_count, sizeof(char *), cmp_entries);
+
+	for (size_t i = 0; i < file_count; i++) {
+		snprintf(fullpath, sizeof(fullpath), "%s/%s", path, entries[i]);
+		print_file_info(fullpath, entries[i], width_uid, width_gid,
+				width_size);
+		free(entries[i]);
+	}
+
+	free(entries);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	if (argc > 1)
+		return list_files(argv[1]);
+	return list_files(".");
+}
+