Eiffel: how do I do a system call? - eiffel

Question

Id like to uncompress a file with bzip2 myFile.bz2 which class do I have to use for that?
I tried to find it into base kernel documentation which made the most sense for me and didn't find it

Answer 1

This works:
make
local
l_env:EXECUTION_ENVIRONMENT
do
create l_env
l_env.system ("bzip2 test.txt")
end

Answer 2

My final solution working on linux with pipes is following:
feature -- Commands
piped_command_result (a_command: STRING): detachable PROCESS_COMMAND_RESULT
-- https://groups.google.com/forum/#!topic/eiffel-users/O9KEtBSPrf4
local
l_cmd: READABLE_STRING_32
l_args: ARRAYED_LIST [READABLE_STRING_32]
l_proc: like {BASE_PROCESS_FACTORY}.process_launcher
l_err, l_res: STRING
l_err_spec, l_res_spec: SPECIAL [NATURAL_8]
do
create l_res.make (0)
create l_err.make (0)
create l_res_spec.make_filled (0, 1024)
create l_err_spec.make_filled (0, 1024)
l_cmd := (create {EXECUTION_ENVIRONMENT}).default_shell
if l_cmd.is_empty then
l_cmd := {STRING_32} "/bin/bash" -- or either "/bin/sh"
end
create l_args.make (2)
l_args.extend ("-c")
l_args.extend (a_command)
l_proc := (create {BASE_PROCESS_FACTORY}).process_launcher (l_cmd, l_args, Void)
l_proc.set_hidden (True)
l_proc.set_separate_console (False)
l_proc.redirect_output_to_stream
l_proc.redirect_error_to_stream
l_proc.launch
check
process_launched: l_proc.launched
then
-- read output
from
until
l_proc.has_output_stream_closed or l_proc.has_output_stream_error
loop
l_proc.read_output_to_special (l_res_spec)
append_special_of_natural_8_to_string_8 (l_res_spec, l_res)
end
-- read error
from
until
l_proc.has_error_stream_closed or l_proc.has_error_stream_error
loop
l_proc.read_error_to_special (l_err_spec)
append_special_of_natural_8_to_string_8 (l_err_spec, l_err)
end
l_proc.wait_for_exit
create Result.make (l_proc.exit_code, l_res, l_err)
end
ensure
instance_free: Class
end
feature {NONE} -- Implementation
append_special_of_natural_8_to_string_8 (spec: SPECIAL [NATURAL_8]; a_output: STRING)
local
i,n: INTEGER
do
from
i := spec.lower
n := spec.upper
until
i > n
loop
a_output.append_code (spec[i])
i := i + 1
end
ensure
instance_free: Class
end
Credits to google groups eiffel users
Note that with another user like an app launched by apache, you have to check your environment variables and $PATH so that it can work!