ls.c

手机嵌入式Linux下可用的busybox源码

/* vi: set sw=4 ts=4: */
/*
 * tiny-ls.c version 0.1.0: A minimalist 'ls'
 * Copyright (C) 1996 Brian Candler <[e-mail]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * To achieve a small memory footprint, this version of 'ls' doesn't do any
 * file sorting, and only has the most essential command line switches
 * (i.e., the ones I couldn't live without :-) All features which involve
 * linking in substantial chunks of libc can be disabled.
 *
 * Although I don't really want to add new features to this program to
 * keep it small, I *am* interested to receive bug fixes and ways to make
 * it more portable.
 *
 * KNOWN BUGS:
 * 1. ls -l of a directory doesn't give "total <blocks>" header
 * 2. ls of a symlink to a directory doesn't list directory contents
 * 3. hidden files can make column width too large
 *
 * NON-OPTIMAL BEHAVIOUR:
 * 1. autowidth reads directories twice
 * 2. if you do a short directory listing without filetype characters
 *    appended, there's no need to stat each one
 * PORTABILITY:
 * 1. requires lstat (BSD) - how do you do it without?
 */

enum {
	TERMINAL_WIDTH = 80,		/* use 79 if terminal has linefold bug */
	COLUMN_WIDTH = 14,			/* default if AUTOWIDTH not defined */
	COLUMN_GAP = 2,				/* includes the file type char */
};


/************************************************************************/

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>
#include "busybox.h"

#ifdef BB_FEATURE_LS_TIMESTAMPS
#include <time.h>
#endif

#ifndef MAJOR
#define MAJOR(dev) (((dev)>>8)&0xff)
#define MINOR(dev) ((dev)&0xff)
#endif

/* what is the overall style of the listing */
enum {
STYLE_AUTO = 0,
STYLE_LONG = 1,		/* one record per line, extended info */
STYLE_SINGLE = 2,		/* one record per line */
STYLE_COLUMNS = 3		/* fill columns */
};

/* 51306 lrwxrwxrwx  1 root     root         2 May 11 01:43 /bin/view -> vi* */
/* what file information will be listed */
#define LIST_INO		(1<<0)
#define LIST_BLOCKS		(1<<1)
#define LIST_MODEBITS	(1<<2)
#define LIST_NLINKS		(1<<3)
#define LIST_ID_NAME	(1<<4)
#define LIST_ID_NUMERIC	(1<<5)
#define LIST_SIZE		(1<<6)
#define LIST_DEV		(1<<7)
#define LIST_DATE_TIME	(1<<8)
#define LIST_FULLTIME	(1<<9)
#define LIST_FILENAME	(1<<10)
#define LIST_SYMLINK	(1<<11)
#define LIST_FILETYPE	(1<<12)
#define LIST_EXEC		(1<<13)

/* what files will be displayed */
#define DISP_NORMAL		(0)		/* show normal filenames */
#define DISP_DIRNAME	(1<<0)	/* 2 or more items? label directories */
#define DISP_HIDDEN		(1<<1)	/* show filenames starting with .  */
#define DISP_DOT		(1<<2)	/* show . and .. */
#define DISP_NOLIST		(1<<3)	/* show directory as itself, not contents */
#define DISP_RECURSIVE	(1<<4)	/* show directory and everything below it */
#define DISP_ROWS		(1<<5)	/* print across rows */

#ifdef BB_FEATURE_LS_SORTFILES
/* how will the files be sorted */
static const int SORT_FORWARD = 0;		/* sort in reverse order */
static const int SORT_REVERSE = 1;		/* sort in reverse order */
static const int SORT_NAME = 2;		/* sort by file name */
static const int SORT_SIZE = 3;		/* sort by file size */
static const int SORT_ATIME = 4;		/* sort by last access time */
static const int SORT_CTIME = 5;		/* sort by last change time */
static const int SORT_MTIME = 6;		/* sort by last modification time */
static const int SORT_VERSION = 7;		/* sort by version */
static const int SORT_EXT = 8;		/* sort by file name extension */
static const int SORT_DIR = 9;		/* sort by file or directory */
#endif

#ifdef BB_FEATURE_LS_TIMESTAMPS
/* which of the three times will be used */
static const int TIME_MOD = 0;
static const int TIME_CHANGE = 1;
static const int TIME_ACCESS = 2;
#endif

#define LIST_SHORT		(LIST_FILENAME)
#define LIST_ISHORT		(LIST_INO | LIST_FILENAME)
#define LIST_LONG		(LIST_MODEBITS | LIST_NLINKS | LIST_ID_NAME | \
						LIST_SIZE | LIST_DATE_TIME | LIST_FILENAME | \
						LIST_SYMLINK)
#define LIST_ILONG		(LIST_INO | LIST_LONG)

static const int SPLIT_DIR = 0;
static const int SPLIT_FILE = 1;
static const int SPLIT_SUBDIR = 2;

#define TYPEINDEX(mode) (((mode) >> 12) & 0x0f)
#define TYPECHAR(mode)  ("0pcCd?bB-?l?s???" [TYPEINDEX(mode)])
#if defined(BB_FEATURE_LS_FILETYPES) || defined(BB_FEATURE_LS_COLOR)
#define APPCHAR(mode)   ("\0|\0\0/\0\0\0\0\0@\0=\0\0\0" [TYPEINDEX(mode)])
#endif
/* colored LS support by JaWi, [e-mail] */
#ifdef BB_FEATURE_LS_COLOR
static int show_color = 0;
#define COLOR(mode)   ("\000\043\043\043\042\000\043\043"\
					   "\000\000\044\000\043\000\000\040" [TYPEINDEX(mode)])
#define ATTR(mode)   ("\00\00\01\00\01\00\01\00"\
					  "\00\00\01\00\01\00\00\01" [TYPEINDEX(mode)])
#endif

/*
 * a directory entry and its stat info are stored here
 */
struct dnode {				/* the basic node */
    char *name;				/* the dir entry name */
    char *fullname;			/* the dir entry name */
    struct stat dstat;		/* the file stat info */
    struct dnode *next;		/* point at the next node */
};
typedef struct dnode dnode_t;

static struct dnode **list_dir(char *);
static struct dnode **dnalloc(int);
static int list_single(struct dnode *);

static unsigned int disp_opts;
static unsigned int style_fmt;
static unsigned int list_fmt;
#ifdef BB_FEATURE_LS_SORTFILES
static unsigned int sort_opts;
static unsigned int sort_order;
#endif
#ifdef BB_FEATURE_LS_TIMESTAMPS
static unsigned int time_fmt;
#endif
#ifdef BB_FEATURE_LS_FOLLOWLINKS
static unsigned int follow_links=FALSE;
#endif

static unsigned short column = 0;
#ifdef BB_FEATURE_AUTOWIDTH
static unsigned short terminal_width = TERMINAL_WIDTH;
static unsigned short column_width = COLUMN_WIDTH;
static unsigned short tabstops = COLUMN_GAP;
#else
static unsigned short column_width = COLUMN_WIDTH;
#endif

static int status = EXIT_SUCCESS;

#ifdef BB_FEATURE_HUMAN_READABLE
static unsigned long ls_disp_hr = 0;
#endif

static int my_stat(struct dnode *cur)
{
#ifdef BB_FEATURE_LS_FOLLOWLINKS
	if (follow_links == TRUE) {
		if (stat(cur->fullname, &cur->dstat)) {
			perror_msg("%s", cur->fullname);
			status = EXIT_FAILURE;
			free(cur->fullname);
			free(cur);
			return -1;
		}
	} else
#endif
	if (lstat(cur->fullname, &cur->dstat)) {
		perror_msg("%s", cur->fullname);
		status = EXIT_FAILURE;
		free(cur->fullname);
		free(cur);
		return -1;
	}
	return 0;
}

static void newline(void)
{
    if (column > 0) {
        putchar('\n');
        column = 0;
    }
}

/*----------------------------------------------------------------------*/
#ifdef BB_FEATURE_LS_COLOR
static char fgcolor(mode_t mode)
{
	/* Check if the file is missing */
	if ( errno == ENOENT ) {
		errno = 0;
		/* Color it red! */
	    return '\037';
	}
	if ( LIST_EXEC && S_ISREG( mode )
	    && ( mode & ( S_IXUSR | S_IXGRP | S_IXOTH ) ) ) 
		return COLOR(0xF000);	/* File is executable ... */
	return COLOR(mode);
}

/*----------------------------------------------------------------------*/
static char bgcolor(mode_t mode)
{
	if ( LIST_EXEC && S_ISREG( mode )
	    && ( mode & ( S_IXUSR | S_IXGRP | S_IXOTH ) ) ) 
		return ATTR(0xF000);	/* File is executable ... */
	return ATTR(mode);
}
#endif

/*----------------------------------------------------------------------*/
#if defined(BB_FEATURE_LS_FILETYPES) || defined(BB_FEATURE_LS_COLOR)
static char append_char(mode_t mode)
{
	if ( !(list_fmt & LIST_FILETYPE))
		return '\0';
	if ((list_fmt & LIST_EXEC) && S_ISREG(mode)
	    && (mode & (S_IXUSR | S_IXGRP | S_IXOTH))) return '*';
		return APPCHAR(mode);
}
#endif

/*----------------------------------------------------------------------*/
static void nexttabstop( void )
{
	static short nexttab= 0;
	int n=0;

	if (column > 0) {
		n= nexttab - column;
		if (n < 1) n= 1;
		while (n--) {
			putchar(' ');
			column++;
		}
	}
	nexttab= column + column_width + COLUMN_GAP; 
}

/*----------------------------------------------------------------------*/
static int is_subdir(struct dnode *dn)
{
	return (S_ISDIR(dn->dstat.st_mode) && strcmp(dn->name, ".") != 0 &&
			strcmp(dn->name, "..") != 0);
}

static int countdirs(struct dnode **dn, int nfiles)
{
	int i, dirs;

	if (dn==NULL || nfiles < 1) return(0);
	dirs= 0;
	for (i=0; i<nfiles; i++) {
		if (S_ISDIR(dn[i]->dstat.st_mode)) dirs++;
	}
	return(dirs);
}

static int countsubdirs(struct dnode **dn, int nfiles)
{
	int i, subdirs;

	if (dn == NULL || nfiles < 1) return 0;
	subdirs = 0;
	for (i = 0; i < nfiles; i++)
		if (is_subdir(dn[i]))
			subdirs++;
	return subdirs;
}

static int countfiles(struct dnode **dnp)
{
	int nfiles;
	struct dnode *cur;

	if (dnp == NULL) return(0);
	nfiles= 0;
	for (cur= dnp[0];  cur->next != NULL ; cur= cur->next) nfiles++;
	nfiles++;
	return(nfiles);
}

/* get memory to hold an array of pointers */
static struct dnode **dnalloc(int num)
{
	struct dnode **p;

	if (num < 1) return(NULL);

	p= (struct dnode **)xcalloc((size_t)num, (size_t)(sizeof(struct dnode *)));
	return(p);
}

#ifdef BB_FEATURE_LS_RECURSIVE
static void dfree(struct dnode **dnp)
{
	struct dnode *cur, *next;

	if(dnp == NULL) return;

	cur=dnp[0];
	while (cur != NULL) {
		if (cur->fullname != NULL) free(cur->fullname);	/* free the filename */
		next= cur->next;
		free(cur);				/* free the dnode */
		cur= next;
	}
	free(dnp);	/* free the array holding the dnode pointers */
}
#endif

static struct dnode **splitdnarray(struct dnode **dn, int nfiles, int which)
{
	int dncnt, i, d;
	struct dnode **dnp;

	if (dn==NULL || nfiles < 1) return(NULL);

	/* count how many dirs and regular files there are */
	if (which == SPLIT_SUBDIR)
		dncnt = countsubdirs(dn, nfiles);
	else {
		dncnt= countdirs(dn, nfiles); /* assume we are looking for dirs */
		if (which == SPLIT_FILE)
			dncnt= nfiles - dncnt;  /* looking for files */
	}

	/* allocate a file array and a dir array */
	dnp= dnalloc(dncnt);

	/* copy the entrys into the file or dir array */
	for (d= i=0; i<nfiles; i++) {
		if (which == SPLIT_DIR) {
			if (S_ISDIR(dn[i]->dstat.st_mode)) {
				dnp[d++]= dn[i];
			}  /* else skip the file */
		} else if (which == SPLIT_SUBDIR) {
			if (is_subdir(dn[i])) {
				dnp[d++]= dn[i];
			}  /* else skip the file or dir */
		} else {
			if (!(S_ISDIR(dn[i]->dstat.st_mode))) {
				dnp[d++]= dn[i];
			}  /* else skip the dir */
		}
	}
	return(dnp);
}

/*----------------------------------------------------------------------*/
#ifdef BB_FEATURE_LS_SORTFILES
static int sortcmp(struct dnode *d1, struct dnode *d2)
{
	int cmp, dif;

	cmp= 0;
	if (sort_opts == SORT_SIZE) {
		dif= (int)(d1->dstat.st_size - d2->dstat.st_size);
	} else if (sort_opts == SORT_ATIME) {
		dif= (int)(d1->dstat.st_atime - d2->dstat.st_atime);
	} else if (sort_opts == SORT_CTIME) {
		dif= (int)(d1->dstat.st_ctime - d2->dstat.st_ctime);
	} else if (sort_opts == SORT_MTIME) {
		dif= (int)(d1->dstat.st_mtime - d2->dstat.st_mtime);
	} else if (sort_opts == SORT_DIR) {
		dif= S_ISDIR(d1->dstat.st_mode) - S_ISDIR(d2->dstat.st_mode);
	/* } else if (sort_opts == SORT_VERSION) { */
	/* } else if (sort_opts == SORT_EXT) { */
	} else {    /* assume SORT_NAME */
		dif= 0;
	}

	if (dif > 0) cmp= -1;
	if (dif < 0) cmp=  1;
	if (dif == 0) {
		/* sort by name- may be a tie_breaker for time or size cmp */
		dif= strcmp(d1->name, d2->name);
		if (dif > 0) cmp=  1;
		if (dif < 0) cmp= -1;
	}

	if (sort_order == SORT_REVERSE) {
		cmp=  -1 * cmp;
	}
	return(cmp);
}

/*----------------------------------------------------------------------*/
static void shellsort(struct dnode **dn, int size)
{
	struct dnode *temp;
	int gap, i, j;

	/* shell short the array */
	if(dn==NULL || size < 2) return;

	for (gap= size/2; gap>0; gap /=2) {
		for (i=gap; i<size; i++) {
			for (j= i-gap; j>=0; j-=gap) {
				if (sortcmp(dn[j], dn[j+gap]) <= 0)
					break;
				/* they are out of order, swap them */
				temp= dn[j];
				dn[j]= dn[j+gap];
				dn[j+gap]= temp;
			}
		}
	}
}
#endif

/*----------------------------------------------------------------------*/
static void showfiles(struct dnode **dn, int nfiles)
{
	int i, ncols, nrows, row, nc;
#ifdef BB_FEATURE_AUTOWIDTH
	int len;
#endif

	if(dn==NULL || nfiles < 1) return;

#ifdef BB_FEATURE_AUTOWIDTH
	/* find the longest file name-  use that as the column width */
	column_width= 0;
	for (i=0; i<nfiles; i++) {
		len= strlen(dn[i]->name) +
			((list_fmt & LIST_INO) ? 8 : 0) +
			((list_fmt & LIST_BLOCKS) ? 5 : 0)
			;
		if (column_width < len) 
			column_width= len;
	}
	if (column_width >= 1)
		ncols = (int)(terminal_width / (column_width + COLUMN_GAP));
	else {
		ncols = 1;
		column_width = COLUMN_WIDTH;
	}
#else
	ncols= TERMINAL_WIDTH;
#endif
	switch (style_fmt) {
		case STYLE_LONG:	/* one record per line, extended info */
		case STYLE_SINGLE:	/* one record per line */
			ncols= 1;
			break;
	}

	if (ncols > 1) {
		nrows = nfiles / ncols;
	} else {
		nrows = nfiles;
		ncols = 1;
	}