From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: Victor Porton Newsgroups: comp.lang.ada Subject: Re: Execute an OS command and capture output Date: Mon, 13 Nov 2017 22:16:02 +0200 Organization: Aioe.org NNTP Server Message-ID: References: NNTP-Posting-Host: dDnBrl5M0tnZkgU+KABVxA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8Bit X-Complaints-To: abuse@aioe.org User-Agent: KNode/4.14.10 X-Notice: Filtered by postfilter v. 0.8.2 Xref: feeder.eternal-september.org comp.lang.ada:48863 Date: 2017-11-13T22:16:02+02:00 List-Id: Dmitry A. Kazakov wrote: > On 2017-11-13 19:52, Victor Porton wrote: >> Dmitry A. Kazakov wrote: >> >>> On 2017-11-13 17:38, Victor Porton wrote: >>>> I need a (preferably portable, but only Linux would be well) way to >>>> execute an OS command with some input in stdin which I provide and >>>> capture the output from stdout. >>> >>> It is a vague question because there are numerous methods of how the >>> input, output and error pipes are handled. E.g. by 0, 1, 2 tasks. >>> >>> Anyway see: >>> >>> 1. GNAT's System.OS_Lib.Spawn, System.OS_Lib.Non_Blocking_Spawn. >> >> Where are docs for this? I sought Google but not found. > > Only package specification AFAIK. But it is quite easy to understand > because Spawn and Non_Blocking_Spawn are very low-level. > >>> 2. A more comfortable method would be to use GTK bindings (GLib >>> actually): >>> >>> http://www.dmitry-kazakov.de/ada/gtkada_contributions.htm#10 >> >> I don't want my software to depend on GTK as it is Web based. > > GTK is not Web-based. It is written in C. I meant that my software (not GTK) is Web based. >> Is it possible to extract this code and use it separately? > > Sources of GLib are freely available. > > But it would be too complicated, especially under Windows were the GLib > implementation uses a helper process. It seems we need a helper process on Linux/Unix too: >From https://codelabs.ch/spawn-manager/index.html The Ada spawn manager implements the concept described in the GNAT GPL package System.OS_Lib. It is used to solve the problem of spawning processes at arbitrary times from multitasking Ada programs: If the parent is using tasking, and needs to spawn subprocesses at arbitrary times, one technique is for the parent to spawn (very early) a particular spawn-manager subprocess whose job is to spawn other processes. The spawn- manager avoids tasking. The parent sends messages to the spawn-manager requesting it to spawn processes, using whatever inter-process communication mechanism you like, such as sockets. SYSTEM.OS_LIB specification — GNAT COMPILER COMPONENTS So I am going to write patches to Ada Spawn Manager instead of using an existing solution, because my software is going to be multi-tasking. In your opinion, is it really necessary? or can I use an existing solution? -- Victor Porton - http://portonvictor.org