add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/du.c

@@ -0,0 +1,237 @@
+/* du - report on disk usage		Author: Alistair G. Crooks */
+
+/*
+ *	du.c		1.1	27/5/87		agc	Joypace Ltd.
+ *			1.2	24 Mar 89	nick@nswitgould.oz
+ *			1.3	31 Mar 89	nick@nswitgould.oz
+ *			1.4	22 Feb 90	meulenbr@cst.prl.philips.nl
+ *
+ *	Copyright 1987, Joypace Ltd., London UK. All rights reserved.
+ *	This code may be freely distributed, provided that this notice
+ *	remains attached.
+ *
+ *	du - a public domain interpretation of du(1).
+ *
+ *  1.2: 	Fixed bug involving 14 character long filenames
+ *  1.3:	Add [-l levels] option to restrict printing.
+ *  1.4:	Added processing of multiple arguments
+ *
+ */
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <blocksize.h>
+#include <stdio.h>
+
+char *prog;			/* program name */
+char *optstr = "asl:";		/* -a and -s arguments */
+int silent = 0;			/* silent mode */
+int all = 0;			/* all directory entries mode */
+char *startdir = ".";		/* starting from here */
+int levels = 255;		/* # of directory levels to print */
+
+#define	LINELEN 256
+
+#define DIRNAMELEN 14
+#define	LSTAT stat
+typedef struct _dirstr {
+  ino_t inum;
+  char d_name[DIRNAMELEN];
+} DIR;
+DIR dir;
+
+typedef struct _alstr {
+  int al_dev;
+  ino_t al_inum;
+} ALREADY;
+
+#define	MAXALREADY	50
+ALREADY already[MAXALREADY];
+int alc = 0;
+
+/*
+ *	myindex - stop the scanf bug
+ */
+char *myindex(s, c)
+register char *s;
+register char c;
+{
+  for (; *s; s++)
+	if (*s == c) return(s);
+  return(NULL);
+}
+
+
+/*
+ *	getopt - parse the arguments given.
+ *	retrieved from net.sources
+ */
+int opterr = 1;
+int optind = 1;
+int optopt;
+char *optarg;
+
+#define BADCH	(int)'?'
+#define EMSG	""
+#define TELL(s)	fputs(*nargv, stderr); fputs(s, stderr);\
+  fputc(optopt, stderr); fputc('\n', stderr);\
+  return(BADCH);
+
+int getopt(nargc, nargv, ostr)
+int nargc;
+char **nargv;
+char *ostr;
+{
+  register char *oli;
+  static char *place = EMSG;
+
+  if (!*place) {
+	if (optind >= nargc || *(place = nargv[optind]) != '-' || !*++place)
+		return(EOF);
+	if (*place == '-') {
+		++optind;
+		return(EOF);
+	}
+  }
+  if ((optopt = (int) *place++) == (int) ':' || !(oli = myindex(ostr, optopt))) {
+	if (!*place) ++optind;
+	TELL(": illegal option -- ");
+  }
+  if (*++oli != ':') {
+	optarg = NULL;
+	if (!*place) ++optind;
+  } else {
+	if (*place)
+		optarg = place;
+	else if (nargc <= ++optind) {
+		place = EMSG;
+		TELL(": option requires an argument -- ");
+	} else
+		optarg = nargv[optind];
+	place = EMSG;
+	++optind;
+  }
+  return(optopt);
+}
+
+/*
+ *	makedname - make the pathname from the directory name, and the
+ *	directory entry, placing it in out. If this would overflow,
+ *	return 0, otherwise 1.
+ */
+int makedname(d, f, out, outlen)
+char *d;
+char *f;
+char *out;
+int outlen;
+{
+  char *cp;
+  int length;
+
+  /* Find length (1-14) of directory entry */
+  cp = f;
+  for (length = 0; *cp && (length < 14); ++cp) ++length;
+
+  if (strlen(d) + length + 2 > outlen) return(0);
+  for (cp = out; *d; *cp++ = *d++);
+  if (*(cp - 1) != '/') *cp++ = '/';
+  while (length--) *cp++ = *f++;
+  *cp = '\0';
+  return(1);
+}
+
+/*
+ *	done - have we encountered (dev, inum) before? Returns 1 for yes,
+ *	0 for no, and remembers (dev, inum).
+ */
+int done(dev, inum)
+int dev;
+ino_t inum;
+{
+  register ALREADY *ap;
+  register int i;
+  int ret = 0;
+
+  for (i = 0, ap = already; i < alc; ap++, i++)
+	if (ap->al_dev == dev && ap->al_inum == inum) {
+		ret = 1;
+		break;
+	}
+  if (alc < MAXALREADY) {
+	already[alc].al_dev = dev;
+	already[alc++].al_inum = inum;
+  }
+  return(ret);
+}
+
+/*
+ *	dodir - process the directory d. Return the long size (in blocks)
+ *	of d and its descendants.
+ */
+long dodir(d, thislev)
+char *d;
+int thislev;
+{
+  struct stat s;
+  long total = 0L;
+  char dent[LINELEN];
+  int fd;
+
+  if ((fd = open(d, O_RDONLY)) < 0) return(0L);
+  while (read(fd, &dir, sizeof(dir)) > 0) {
+	if (strcmp(dir.d_name, ".") == 0 ||
+	    strcmp(dir.d_name, "..") == 0)
+		continue;
+	if (dir.inum == 0) continue;
+	if (!makedname(d, dir.d_name, dent, sizeof(dent))) continue;
+	if (LSTAT(dent, &s) < 0) continue;
+	if (s.st_nlink > 1 && done(s.st_dev, s.st_ino)) continue;
+	if ((s.st_mode & S_IFMT) == S_IFDIR)
+		total += dodir(dent, thislev - 1);
+	switch (s.st_mode & S_IFMT) {
+	    case S_IFREG:
+	    case S_IFDIR:
+		total += (s.st_size + BLOCK_SIZE) / BLOCK_SIZE;
+		break;
+	}
+	if (all && (s.st_mode & S_IFMT) != S_IFDIR)
+		if (thislev > 0)	/* this is correct - file in subdir */
+			printf("%ld\t%s\n",
+				(s.st_size + BLOCK_SIZE) / BLOCK_SIZE, dent);
+  }
+  close(fd);
+  if (!silent)
+	if (thislev >= 0)	/* this is correct - subdir itself */
+		printf("%ld\t%s\n", total, d);
+  return(total);
+}
+
+/*
+ *	OK, here goes...
+ */
+main(argc, argv)
+int argc;
+char **argv;
+{
+  long tot;
+  int c;
+
+  prog = argv[0];
+  while ((c = getopt(argc, argv, optstr)) != EOF) switch (c) {
+	    case 'a':	all = 1;	break;
+	    case 's':	silent = 1;	break;
+	    case 'l':	levels = atoi(optarg);	break;
+	    default:
+		fprintf(stderr,
+			"Usage: %s [-a] [-s] [-l levels] [startdir]\n", prog);
+		exit(1);
+	}
+  do {
+    if (optind < argc) startdir = argv[optind++];
+    tot = dodir(startdir, levels);
+    if (silent) printf("%ld\t%s\n", tot, startdir);
+  } while (optind < argc);
+  exit(0);
+}