Summary of how to remove file with NULL names

[Mark E. Sunderlin]

Here is the consensis of the net on how to remove files with
strange and weird characters in there names.  Thanks to all the
below who responded to my queery.

uokmet!kwthomas,mtgzy!ecl,necis!geo,pegasus!hansen,BRL.ARPA!gwyn
jplgodo!steve ,and Robert Sanford whose address I lost in
the depths of vi and lines over 80 columns long.

>The files have characters over \177 (decimal = 127) in them.  /bin/sh doesn't
>expand such files correctly, as the upper bit is an internal flag meaning
>"this character is quoted" in sh.  So it loses the upper bits on the final
>parse pass or thereabouts.  So "rm" gets a nonexistent file name.
>---------------------------------------------------------------------
>Here is a program that uses the "unlink" system call to remove
>files with funky names. Be careful when using this program
>because it can remove just about anything it wants. You describe
>the desired file(s) by using valid filename characters or a
>backslash followed by three characters in the range of [0-7]
>(octal (gasp!) representation of the character). One example will
>follow the program.
>
>/*************************/
>/*
>	rmjunk.c
>
>	author: Robert Sanford
>	usage: rmjunk file [file ...]
>*/
>
>
>#include <stdio.h>
>#include <errno.h>
>
>
>main ( ac, av )
>	int ac;
>	char **av;
>{
>	char *ip;
>	char *op;
>	char buf[ 200 ];
>
>	for (av++; *av; av++)
>	{
>		for (ip = *av, op = buf; *ip;)
>			if (*ip == '\\')
>			{
>				*op++ = ((ip[1] - '0')*64) + ((ip[2] - '0')*8) +
>					(ip[3] - '0');
>				ip += 4;
>			}
>			else
>				*op++ = *ip++;
>		*op = 0;
>		if (unlink( buf ) < 0)
>		{
>			xdump( stderr, buf );
>			fprintf(stderr, "rmjunk(%s): FAILED errno=%d\n", *av,
>				errno);
>		}
>	}
>}
>
>xdump ( fp, bp )
>	FILE *fp;
>	char *bp;
>{
>	fputc( '"', fp );
>
>	for (; *bp; bp++)
>		if (*bp >= ' ' && *bp <= '~')
>			fputc( *bp, fp );
>		else
>			fprintf(fp, "\\%03o", *bp);
>
>	fputc( '"', fp );
>	fputc( '\n', fp );
>}
>/*************************/
>
>The best way to identify the exact name of the file you want to remove
>is to dump the directory:
>
>	od -c .
>
>0000000 005   `   .  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0
>0000020  \0 002   .   .  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0
>0000040 005   a   .   p   r   o   f   i   l   e  \0  \0  \0  \0  \0  \0
>0000100 005   c   .   n   e   w   s   r   c  \0  \0  \0  \0  \0  \0  \0
>0000140 005   s   .   m   a   c   s  \0  \0  \0  \0  \0  \0  \0  \0  \0
>0000160 005   }   .   n   e   w   s   _   t   i   m   e  \0  \0  \0  \0
>0000420 005 345   r   e   a   l   t   i   m   e   2  \0  \0  \0  \0  \0
>0000440 005 346  \001 e   p   a   r   t   2  \0  \0  \0  \0  \0  \0  \0
>
>(I'm assuming you have Sys.V fixed size directory entries.) In this example
>the last entry is garbage and needs to be removed. (The first two bytes of
>each entry are the i-node number. Isn't it convenient that the length of
>a directory entry is the same as the number of characters "od" displays
>on a line !) Using my "rmjunk" program, you would enter:
>
>	unlink '\001epart2'
>
>This SHOULD yield the desired results. :-)
-- 
_________________________________________________________________________
UUCP:	(1) seismo!dolqci!irsdcp!scsnet!sunder		Mark E. Sunderlin
	(2) ihnp4!chinet!megabyte			aka Dr. Megabyte
CIS:	74026,3235					(202) 634-2529
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