=====Manipulating filenames and pathnames=====

//by Jonathan Harston//\\ \\  Here are some code fragments and routines to manipulate various filenames and pathnames.\\ \\ 
===== Root directory =====
**FNf_root()** extracts the root directory from the supplied path. You can't just look for a colon specifying a drive, as the program may have been run with a Uniform Naming Convention path (see [[http://en.wikipedia.org/wiki/Path_(computing)#Uniform_Naming_Convention|Wikipedia]]). Also, the path may be surrounded by quotes, which have to be taken care of.\\ \\  FNf_root() will return as per the following examples:\\ 
<code bb4w>
      FNf_root("C:\Documents and Settings\jgh\Admin")  *| -> "C:"
      FNf_root("H:\Apps")                              *| -> "H:"
      FNf_root("\\datastore\Tools\Admin")              *| -> "\\datastore"
      FNf_root("X:")                                   *| -> "X:"
</code>
You could then do, for example:\\ 
<code bb4w>
        PROCcopyfiles(FNf_root(indir$)+"\Data","D:\Backup","*.*")
</code>
\\ 
===== Extracting leafname =====
**FNf_leaf()** will scan through a fully-qualified pathname to find just the leafname - the final part of the path.\\ 
<code bb4w>
        DEF FNf_leaf(A$)
        LOCAL A%:REPEAT:A%=INSTR(A$,"\"):IFA%:A$=MID$(A$,A%+1)
        UNTILA%=0:=A$
</code>
For example, **FNf_leaf("H:\Apps\Admin\Startup.exe")** returns **"Startup.exe"**.\\ \\ 
===== Removing leafname =====
**FNf_path()** will remove the leafname, keeping just the pathname. For example:\\ 
<code bb4w>
        DEF FNf_path(A$):IFINSTR(A$,"\")=0:=A$
        LOCAL A%:REPEATB%=A%:A%=INSTR(A$,"\",A%+1):UNTILA%=0:=LEFT$(A$,B%)
</code>
This lets you use code such as:\\ 
<code bb4w>
      IF out$="" THEN out$=FNf_path(in$)+"output.txt"
</code>
\\ 
===== Removing filename extension =====
**FNf_noext()** will remove an extension from a pathname. Note that you cannot just remove the last four characters, as the extension is not guaranteed to be four characters (eg, ".c"), nor can you simply search for a ".", as the path may have multiple "."s in it (eg **"C:\index.dat\20090721\thumb.db"** or even **"Version1.00\data.file.txt"**).\\ 
<code bb4w>
        DEF FNf_ext(A$):IFINSTR(A$,".")=0:=""
        LOCAL A%:A%=LENA$+1:REPEATA%=A%-1:UNTIL INSTR(".:\",MID$(A$,A%,1))
        IF MID$(A$,A%,1)=".":=MID$(A$,A%) ELSE =""
</code>
You can then use this to do, for example:\\ 
<code bb4w>
      PROCBMP_toGIF(bmpfile$,FNf_noext(bmpfile$)+".gif")
</code>
Note that filenames similar to **".htaccess"** are seen as being all extension and no name.\\ \\ 
===== Finding filename extension =====
**FNf_ext()** will scan through a fully-qualified pathname to find the extension. As with **FNf_noext()**, you cannot just use the last four characters.\\ 
<code bb4w>
        DEF FNf_noext(A$):IFINSTR(A$,".")=0:=A$
        LOCAL A%:A%=LENA$+1:REPEATA%=A%-1:UNTIL INSTR(".:\",MID$(A$,A%,1))
        IFMID$(A$,A%,1)=".":=LEFT$(A$,A%-1) ELSE =A$
</code>
You can then use this to do, for example:\\ 
<code bb4w>
      runapp$=FNMime_Type(FNf_ext(file$))
</code>
\\ 
===== Ensuring full absolute pathnames =====
 It is good practice for programs to access files via fully-specified paths, yet it can also be useful for programs to be able to access certain files relative to some path, such as the directory the program is running in. **FNf_fullpath()** will take a path and a filename and return the full path of a relative filename.\\ 
<code bb4w>
        DEF FNf_fullpath(path$,file$)
        IF INSTR(file$,":")<>0 OR INSTR(file$,"\\")<>0:=file$
        IF RIGHT$(path$,1)<>"\":path$=path$+"\"
        =path$+file$
</code>
It functions as in the following examples.\\ 
<code bb4w>
      FNf_fullpath("C:\EARS","DATA")            *| -> "C:\EARS\DATA"
      FNf_fullpath("C:\EARS","A:\INCOMING")     *| -> "A:\INCOMING"
      FNf_fullpath("C:\EARS","\\system\backup") *| -> "\\system\backup"
</code>