/* 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 *			1.5	09 Jul 91	hp@vmars.tuwien.ac.at *			1.6	01 Oct 92	kjb@cs.vu.nl *			1.7	04 Jan 93	bde *			1.8	19 Sep 94	kjb * *	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 *  1.5:	Fixed processing of multiple arguments. General cleanup. *  1.6:	Use readdir *  1.7:	Merged 1.5 and 1.6. *		Print totals even for non-dirs at top level. *		Count blocks for each dir before printing total for the dir. *		Count blocks for all non-special files. *		Don't clutter link buffer with directories. *  1.8:	Remember all links. */#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <errno.h>#include <limits.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <stdio.h>#include <dirent.h>#define BLOCK_SIZE	1024extern char *optarg;extern int optind;#define	LINELEN		256#define	NR_ALREADY	512#ifdef S_IFLNK#define	LSTAT lstat#else#define	LSTAT stat#endiftypedef struct already {  struct already *al_next;  int al_dev;  ino_t al_inum;  nlink_t al_nlink;} ALREADY;_PROTOTYPE(int main, (int argc, char **argv));_PROTOTYPE(int makedname, (char *d, char *f, char *out, int outlen));_PROTOTYPE(int done, (int dev, Ino_t inum, Nlink_t nlink));_PROTOTYPE(long dodir, (char *d, int thislev));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 = 20000;		/* # of directory levels to print */ALREADY *already[NR_ALREADY];int alc;/* *	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;  length = strlen(f);  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, nlink). */int done(dev, inum, nlink)int dev;ino_t inum;nlink_t nlink;{  register ALREADY **pap, *ap;  pap = &already[(unsigned) inum % NR_ALREADY];  while ((ap = *pap) != NULL) {	if (ap->al_inum == inum && ap->al_dev == dev) {		if (--ap->al_nlink == 0) {			*pap = ap->al_next;			free(ap);		}		return(1);	}	pap = &ap->al_next;  }  if ((ap = malloc(sizeof(*ap))) == NULL) {	fprintf(stderr, "du: Out of memory\n");	exit(1);  }  ap->al_next = NULL;  ap->al_inum = inum;  ap->al_dev = dev;  ap->al_nlink = nlink - 1;  *pap = ap;  return(0);}/* *	dodir - process the directory d. Return the long size (in blocks) *	of d and its descendants. */long dodir(d, thislev)char *d;int thislev;{  int maybe_print;  struct stat s;  long total;  char dent[LINELEN];  DIR *dp;  struct dirent *entry;  if (LSTAT(d, &s) < 0) {	fprintf(stderr,		"%s: %s: %s\n", prog, d, strerror(errno));    	return 0L;  }  total = (s.st_size + (BLOCK_SIZE - 1)) / BLOCK_SIZE;  switch (s.st_mode & S_IFMT) {    case S_IFDIR:	/* Directories should not be linked except to "." and "..", so this	 * directory should not already have been done.	 */	maybe_print = !silent;	if ((dp = opendir(d)) == NULL) break;	while ((entry = readdir(dp)) != NULL) {		if (strcmp(entry->d_name, ".") == 0 ||		    strcmp(entry->d_name, "..") == 0)			continue;		if (!makedname(d, entry->d_name, dent, sizeof(dent))) continue;		total += dodir(dent, thislev - 1);	}	closedir(dp);	break;    case S_IFBLK:    case S_IFCHR:	/* st_size for special files is not related to blocks used. */	total = 0;	/* Fall through. */    default:	if (s.st_nlink > 1 && done(s.st_dev, s.st_ino, s.st_nlink)) return 0L;	maybe_print = all;	break;  }  if (thislev >= levels || (maybe_print && thislev >= 0))	printf("%ld\t%s\n", total, d);  return(total);}int main(argc, argv)int argc;char **argv;{  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++];	alc = 0;	(void) dodir(startdir, levels);  } while (optind < argc);  return(0);}