| Re: findfile on unix bug - help [message #27071 is a reply to message #26927] |
Thu, 04 October 2001 14:32  |
thompson
Messages: 584
Registered: August 1991
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Senior Member |
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"R.G.S." <rgs1967@hotmail.com> writes:
> Hi,
> I have a problem running my code on a unix machine
> (idlv5.4). The command is as follows:
> files = findfile(subdirectory+'*.dat',count=num)
> This does not give me the files in that subdirectory, rather it gives me the
> files in the current folder.
> So now if I do the same command as:
> files = findfile(subdirectory+'*',count=num)
> I do get the entire listing. This is how I work around it,
> however, it is possible that there are files other than the *.dat
> and I want to filter on those. This works in win2000 nicely, so
> what is the problem on the unix side?
I've never seen this behavior on any Unix platform that I've used, and can't
replicate it with IDL/v5.4.1 on my Alpha/OSF workstation. Two things occur to
me:
1. The simplest answer is that the variable subdirectory is ending up as a
blank string. That would definitely cause the behavior you're seeing. Have
you verified that it contains what you think it contains?
2. We've had problems in Unix with findfile when the directory is very large,
but the symptoms of that is that the result ends up being the null string, with
a count of 0. Maybe this is somehow causing your problem, although it doesn't
sound like it.
My colleague Stein Vidar Haugan got around this problem by writing a program
called find_file.pro, which I've appended below. There are some additional
routines which can be found at
ftp://sohoftp.nascom.nasa.gov/solarsoft/gen/idl/
Bill Thompson
;+
; Project : SOHO - CDS
;
; Name : FIND_FILE()
;
; Purpose : Fixing builtin FINDFILE() problem
;
; Explanation : The builtin FINDFILE() function has problems on some unixes
; whenever *a lot* of files are matching the file
; specification. This is due to the fact that filename expansion
; is done by the shell *before* interpreting a command. Too many
; files cause too long commands, which are not accepted. This
; causes FINDFILE() to return an empty list of candidates.
;
; FIND_FILE tries the builtin function first, and whenever the
; returned list of files is empty, it tries to recheck through
; spawning a "find" command.
;
; Since FINDFILE doesn't discriminate between directories, links
; and files, this function will not do this either.
;
; Under unix, however, calls like FINDFILE("*") returns the
; unfiltered output of the shell commmand "ls *", including
; colon-terminated lines for each subdirectory matching the
; specification and empty lines separating each subdirectory
; listing. Such silly effects are not implemented in the "find"
; version. Be warned, however, that these effects are present
; when the builtin function does not "fail" due to a too long
; file list.
;
; It is possible (under unix) to use the "find" method as
; default by setting the keyword /USEFIND (no effect under other
; operating systems).
;
; Use : files = find_file(file_specification)
;
; Inputs : file_specification : A scalar string used to find
; files. See FINDFILE()
;
; Opt. Inputs : None.
;
; Outputs : Returns a list of files or a blank string if none found.
;
; Opt. Outputs:
;
; Keywords : COUNT : Returns the number of files
;
; USEFIND : Always use a spawned "find" command under unix.
; No effect under other operating systems.
;
; NODOT : Apply a filter to the results from find to prevent
; finding the directory itself in a large file expansion.
; eg 'find_file,"foo/*"' returns ("foo/","foo/a",...)
; but 'find_file,"foo/*",/nodot' returns
; ("foo/a","foo/b",...) without the leading "foo/".
; This behavior is closer to the behavior of findfile()
; without the long-directory braindamage. It is
; *not* the default so as not to break heritage
; code that uses find_file().
;
; Calls : BREAD_FILE, FINDFILE, SPAWN
;
; Common : None
;
; Restrictions: As for FINDFILE
;
; Side effects: None, hopefully
;
; Category : Utilities, Operating_system
;
; Prev. Hist. : Lots of problems with FINDFILE is hopefully history.
;
; Written : S.V.H. Haugan, UiO, 12 April 1996
;
; Modified : Version 2, SVHH, 10 June 1996
; Moved the CD,curr_path command to avoid
; returns without resetting path.
; Version 3, SVHH, 26 June 1996
; Took away the -type f argument to find, added
; /USEFIND keyword.
; : Added /nodot keyword C. DeForest 9-August-1998
;
; Version : 3, 26 June 1996
;-
FUNCTION find_file,file_specification,count=count,usefind=usefind,nod ot=nodot
count = 0
use_find = KEYWORD_SET(usefind) AND os_family() EQ 'unix'
IF NOT use_find AND N_PARAMS() EQ 0 THEN BEGIN
result = findfile(count = count)
RETURN,result ; Unix doesn't have problems with this
END
IF N_PARAMS() EQ 0 THEN file_specification = '*'
IF file_specification EQ '' THEN file_specification = '*'
IF NOT use_find THEN result = findfile(file_specification,count=count) $
ELSE count = 0
;; Check for problems
IF count EQ 0 AND os_family() EQ 'unix' THEN BEGIN
file = file_specification
break_file,file,disk,dir,filnam,ext
;; Check if directory exists
IF dir NE '' THEN BEGIN
IF (findfile(dir))(0) eq '' THEN RETURN,''
END
;; Temporary switch to that directory
IF dir NE '' THEN cd,dir,current=curr_path
IF filnam+ext EQ '' THEN filnam = '*'
;; Find all matching
spn = ["find",".","-name",filnam+ext,"-print"]
spawn,spn,result,/noshell
;; Switch back to original directory
IF dir NE '' THEN cd,curr_path
IF result(0) EQ '' THEN RETURN,'' ; None matching, return
;; Get rid of current-directory match, if necessary
if keyword_set(nodot) and result(0) eq '.' then $
result = result(1:n_elements(result)-1)
;; Chop off './'
result = STRMID(result,2,1000)
;; Chip out subdirectories (for some reason, the -prune option doesn't
;; work properly, so I have dropped using it).
ix = WHERE(STRPOS(result,'/') EQ -1,count)
IF count EQ 0 THEN RETURN,''
;; Put back the specified (not full) path
result = dir + result(ix)
END
RETURN,result
END
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;
; End of 'findfile.pro'.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;
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