goer@MIDWAY.UCHICAGO.EDU ("Richard L. Goerwitz") (10/21/90)
It's hard to get directory listings from within Icon. Here are
some routines that do this in a generic way. The idea of doing
things generically is to avoid OS-specificity, at least on the
level on which these routines are called (not, in other words,
in the actual mechanics of how to get the listing, which are very
OS-specific).
Anyway, I hope someone finds these routines useful.
-Richard
############################################################################
#
# Name: gdl.icn
#
# Title: Get directory list
#
# Author: Richard L. Goerwitz
#
# Version: 1.2
#
############################################################################
#
# Gdl returns a list containing everything in a directory (whose name
# must be passed as an argument to gdl). Nothing fancy. I use this file
# as a template, modifying the procedures according to the needs of the
# program in which they are used.
#
############################################################################
#
# Requires: UNIX or MS-DOS
#
############################################################################
procedure gdl(dir)
getdir := set_getdir_by_os()
return getdir(dir)
end
procedure set_getdir_by_os()
# Decide how to get a directory, based on whether we are running
# under Unix or MS-DOS.
if find("UNIX", &features)
then return unix_get_dir
else if find("MS-DOS", &features)
then return msdos_get_dir
else stop("Your operating system is not (yet) supported.")
end
procedure msdos_get_dir(dir)
# Returns a sorted list of all filenames (full paths included) in
# directory "dir." The list is sorted. Fails on invalid or empty
# directory. Aborts if temp file cannot be opened.
#
# Temp files can be directed to one or another directory either by
# manually setting the variable temp_dir below, or by setting the
# value of the environment variable TEMPDIR to an appropriate
# directory name.
local in_dir, filename_list, line
static temp_dir
initial {
temp_dir :=
(trim(map(getenv("TEMPDIR"), "/", "\\"), '\\') || "\\") |
".\\"
}
# Get name of tempfile to be used.
temp_name := get_dos_tempname(temp_dir) |
stop("No more available tempfile names!")
# Make sure we have an unambiguous directory name, with backslashes
# instead of Unix-like forward slashes.
dir := trim(map(dir, "/", "\\"), '\\') || "\\"
# Put dir listing into a temp file.
system("dir "||dir||" > "||temp_name)
# Put tempfile entries into a list, removing blank- and
# space-initial lines. Exclude directories (i.e. return file
# names only).
in_dir := open(temp_name,"r") |
stop("Can't open temp file in directory ",temp_dir,".")
filename_list := list()
every filename := ("" ~== !in_dir) do {
match(" ",filename) | find(" <DIR>", filename) & next
# Exclude our own tempfiles (may not always be appropriate).
filename ?:= trim(trim(tab(10)) || "." || tab(13), '. ')
put(filename_list, map(dir || filename))
}
# Clean up.
close(in_dir) & remove(temp_name)
# Check to be sure we actually managed to read some files.
if *filename_list = 0 then fail
else return sort(filename_list)
end
procedure get_dos_tempname(dir)
# Don't clobber existing files. Get a unique temp file name for
# use as a temporary storage site.
every temp_name := dir || "icondir." || right(string(1 to 999),3,"0") do {
temp_file := open(temp_name,"r") | break
close(temp_file)
}
return \temp_name
end
procedure unix_get_dir(dir)
dir := trim(dir, '/') || "/"
filename_list := list()
in_dir := open("/bin/ls -F "||dir, "pr")
every filename := ("" ~== !in_dir) do {
match("/",filename,*filename) & next
put(filename_list, trim(dir || filename, '*'))
}
close(in_dir)
if *filename_list = 0 then fail
else return filename_list
end