;+

; 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       : 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 OS_FAMILY

RETURN, StrLowCase(!Version.OS_Family)

END





FUNCTION find_file,file_specification,count=count,usefind=usefind,nodot=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



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; End of 'findfile.pro'.

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