Initial release

src/file.c

@@ -0,0 +1,114 @@
+/* file.c */
+
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdio.h>
+
+
+/* prefs */
+typedef int Prefs;
+enum { PREFS_d = 6, PREFS_h = 1, PREFS_m = 2, PREFS_M = 4, PREFS_i = 8 };
+
+
+/* file */
+static int _file_do(Prefs * p, char * filename);
+static int _file(Prefs * p, int argc, char * argv[])
+{
+	int ret = 0;
+	int i;
+
+	for(i = 0; i < argc; i++)
+		ret += _file_do(p, argv[i]);
+	return ret;
+}
+
+static int _file_do(Prefs * p, char * filename)
+{
+	struct stat st;
+	int (*statfunc)(const char *, struct stat*) = *p & PREFS_h
+		? lstat : stat;
+
+	printf("%s: ", filename);
+	if(statfunc(filename, &st) != 0)
+	{
+		printf("%s\n", "cannot open file");
+		return 0;
+	}
+	if(S_ISLNK(st.st_mode))
+		printf("%s", "symbolic link to ");
+	if(S_ISBLK(st.st_mode))
+		printf("%s", "block special ");
+	else if(S_ISCHR(st.st_mode))
+		printf("%s", "character special ");
+	else if(S_ISDIR(st.st_mode))
+		printf("%s", "directory ");
+	else if(S_ISFIFO(st.st_mode))
+		printf("%s", "fifo ");
+	else if(S_ISSOCK(st.st_mode))
+		printf("%s", "socket ");
+	else
+	{
+		if(*p & PREFS_i)
+			printf("%s", "regular file ");
+		else if(st.st_size == 0)
+			printf("%s", "empty ");
+		if(st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
+			printf("%s", "executable ");
+	}
+	printf("%s", "data");
+	fputc('\n', stdout);
+	return 0;
+}
+
+
+/* usage */
+static int _usage(void)
+{
+	fprintf(stderr, "%s", "Usage: file [-dh][-M file][-m file] file ...\n\
+       file -i [-h] file ...\n");
+	return 1;
+}
+
+
+/* main */
+int main(int argc, char * argv[])
+{
+	Prefs p = 0;
+	int o;
+
+	while((o = getopt(argc, argv, "dhM:m:i")) != -1)
+	{
+		switch(o)
+		{
+			case 'd':
+				if(p & PREFS_i)
+					return _usage();
+				p |= PREFS_d;
+				break;
+			case 'h':
+				p |= PREFS_h;
+				break;
+			case 'i':
+				if(p != 0)
+					return _usage();
+				p = PREFS_i;
+				break;
+			case 'M':
+				if(p & PREFS_i)
+					return _usage();
+				p |= PREFS_M;
+				break;
+			case 'm':
+				if(p & PREFS_i)
+					return _usage();
+				p |= PREFS_m;
+				break;
+			default:
+				return _usage();
+		}
+	}
+	return _file(&p, argc-optind, &argv[optind]);
+}