Add support for determining name of script JuliaLang#14109

Note that PROGRAM_FILE was chosen as the name for this variable as it
matches the help for the Julia CLI.

NEWS.md

@@ -151,6 +151,8 @@ New language features
 
   * `@__LINE__` special macro now available to reflect invocation source line number ([#12727]).
 
+  * `PROGRAM_FILE` global is now available for determining the name of the running script ([#14114]).
+
 Language changes
 ----------------
 
@@ -1585,6 +1587,7 @@ Too numerous to mention.
 [#7917]: https://github.com/JuliaLang/julia/issues/7917
 [#7992]: https://github.com/JuliaLang/julia/issues/7992
 [#8011]: https://github.com/JuliaLang/julia/issues/8011
+[#8036]: https://github.com/JuliaLang/julia/issues/8036
 [#8089]: https://github.com/JuliaLang/julia/issues/8089
 [#8113]: https://github.com/JuliaLang/julia/issues/8113
 [#8135]: https://github.com/JuliaLang/julia/issues/8135
@@ -1726,12 +1729,15 @@ Too numerous to mention.
 [#12727]: https://github.com/JuliaLang/julia/issues/12727
 [#12739]: https://github.com/JuliaLang/julia/issues/12739
 [#13062]: https://github.com/JuliaLang/julia/issues/13062
+[#13232]: https://github.com/JuliaLang/julia/issues/13232
 [#13338]: https://github.com/JuliaLang/julia/issues/13338
 [#13387]: https://github.com/JuliaLang/julia/issues/13387
 [#13440]: https://github.com/JuliaLang/julia/issues/13440
 [#13465]: https://github.com/JuliaLang/julia/issues/13465
-[#13496]: https://github.com/JuliaLang/julia/issues/13496
 [#13480]: https://github.com/JuliaLang/julia/issues/13480
+[#13496]: https://github.com/JuliaLang/julia/issues/13496
 [#13542]: https://github.com/JuliaLang/julia/issues/13542
 [#13680]: https://github.com/JuliaLang/julia/issues/13680
 [#13681]: https://github.com/JuliaLang/julia/issues/13681
+[#13897]: https://github.com/JuliaLang/julia/issues/13897
+[#14114]: https://github.com/JuliaLang/julia/issues/14114

base/client.jl

@@ -3,6 +3,7 @@
 ## client.jl - frontend handling command line options, environment setup,
 ##             and REPL
 
+PROGRAM_FILE = UTF8String("")
 const ARGS = UTF8String[]
 
 const text_colors = AnyDict(
@@ -209,10 +210,9 @@ function init_bind_addr()
     LPROC.bind_port = UInt16(bind_port)
 end
 
-function process_options(opts::JLOptions, args::Vector{UTF8String})
-    if !isempty(args)
-        arg = first(args)
-        idxs = find(x -> x == "--", args)
+function process_options(opts::JLOptions)
+    if !isempty(ARGS)
+        idxs = find(x -> x == "--", ARGS)
         if length(idxs) > 1
             println(STDERR, "julia: redundant option terminator `--`")
             exit(1)
@@ -266,15 +266,15 @@ function process_options(opts::JLOptions, args::Vector{UTF8String})
             eval(Main, parse_input_line(bytestring(opts.postboot)))
         end
         # load file
-        if !isempty(args) && !isempty(args[1])
+        if !isempty(ARGS) && !isempty(ARGS[1])
             # program
             repl = false
             # remove filename from ARGS
-            shift!(ARGS)
+            global PROGRAM_FILE = UTF8String(shift!(ARGS))
             if !is_interactive
                 ccall(:jl_exit_on_sigint, Void, (Cint,), 1)
             end
-            include(args[1])
+            include(PROGRAM_FILE)
         end
         break
     end
@@ -374,7 +374,7 @@ function _start()
     append!(ARGS, Core.ARGS)
     opts = JLOptions()
     try
-        (quiet,repl,startup,color_set,history_file) = process_options(opts,copy(ARGS))
+        (quiet,repl,startup,color_set,history_file) = process_options(opts)
 
         local term
         global active_repl

base/exports.jl

@@ -182,6 +182,7 @@ export
     JULIA_HOME,
     LOAD_PATH,
     OS_NAME,
+    PROGRAM_FILE,
     STDERR,
     STDIN,
     STDOUT,

doc/manual/getting-started.rst

@@ -51,19 +51,22 @@ argument to the julia command::
 
 As the example implies, the following command-line arguments to julia
 are taken as command-line arguments to the program ``script.jl``, passed
-in the global constant ``ARGS``. ``ARGS`` is also set when script code
-is given using the ``-e`` option on the command line (see the ``julia``
-help output below). For example, to just print the arguments given to a
-script, you could do this::
+in the global constant ``ARGS``. The name of the script itself is passed
+in as the global ``PROGRAM_FILE``. Note that ``ARGS`` is also set when script
+code is given using the ``-e`` option on the command line (see the ``julia``
+help output below) but ``PROGRAM_FILE`` will be empty. For example, to just
+print the arguments given to a script, you could do this::
+
+    $ julia -e 'println(PROGRAM_FILE); for x in ARGS; println(x); end' foo bar
 
-    $ julia -e 'for x in ARGS; println(x); end' foo bar
     foo
     bar
 
 Or you could put that code into a script and run it::
 
-    $ echo 'for x in ARGS; println(x); end' > script.jl
+    $ echo 'println(PROGRAM_FILE); for x in ARGS; println(x); end' > script.jl
     $ julia script.jl foo bar
+    script.jl
     foo
     bar
 

doc/stdlib/constants.rst

@@ -14,6 +14,10 @@ Constants
    A symbol representing the name of the operating system. Possible values
    are ``:Linux``, ``:Darwin`` (OS X), or ``:Windows``.
 
+.. data:: PROGRAM_FILE
+
+   A string containing the script name passed to Julia.
+
 .. data:: ARGS
 
    An array of the command line arguments passed to Julia, as strings.

test/cmdlineargs.jl

@@ -207,20 +207,26 @@ let exename = `$(joinpath(JULIA_HOME, Base.julia_exename())) --precompiled=yes`
     @test !success(`$exename --worker=true`)
 
     # test passing arguments
-    let testfile = tempname()
+    let testfile = tempname(), altfile = tempname()
         try
-            # write a julia source file that just prints ARGS to STDOUT and exits
+            # write a julia source file that just prints PROGRAM_FILE and ARGS to STDOUT and exits
             open(testfile, "w") do io
+                println(io, "println(PROGRAM_FILE)")
                 println(io, "println(ARGS)")
                 println(io, "exit(0)")
             end
-            @test readchomp(`$exename $testfile foo -bar --baz`) ==  "UTF8String[\"foo\",\"-bar\",\"--baz\"]"
-            @test readchomp(`$exename $testfile -- foo -bar --baz`) ==  "UTF8String[\"foo\",\"-bar\",\"--baz\"]"
-            @test readchomp(`$exename -L $testfile -- foo -bar --baz`) ==  "UTF8String[\"foo\",\"-bar\",\"--baz\"]"
+            open(altfile, "w") do io
+                println(io, "println(PROGRAM_FILE)")
+            end
+            @test split(readchomp(`$exename $testfile foo -bar --baz`), '\n') ==  ["$testfile", "UTF8String[\"foo\",\"-bar\",\"--baz\"]"]
+            @test split(readchomp(`$exename $testfile -- foo -bar --baz`), '\n') ==  ["$testfile", "UTF8String[\"foo\",\"-bar\",\"--baz\"]"]
+            @test split(readchomp(`$exename -L $testfile -- foo -bar --baz`), '\n') ==  ["", "UTF8String[\"foo\",\"-bar\",\"--baz\"]"]
+            @test split(readchomp(`$exename -L $altfile $testfile`), '\n') ==  ["", "$testfile", "UTF8String[]"]
             @test !success(`$exename --foo $testfile`)
             @test !success(`$exename -L $testfile -- foo -bar -- baz`)
         finally
             rm(testfile)
+            rm(altfile)
         end
     end