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Full Discussion: Question on forks and pipes
Top Forums UNIX for Advanced & Expert Users Question on forks and pipes Post 302086966 by nathan on Monday 28th of August 2006 11:44:49 PM
Old 08-29-2006
Blowtorch, try piping it to 'cat' or echo $(a.out).

I get the same results.
Code:
$ a.out
0
1
1
$ echo $(a.out)
0 1 0 1
$ a.out | cat
0
1
0
1
$

It stumped me for awhile, but I believe I know why this is happening. The fork() call is copying everything in memory to a child process, including the output buffer. Since the output buffer wasn't flushed before the fork, there was a '0' character in the buffer, and that was also copied. Try flushing the buffer before the fork(). It worked for me.

Code:
int main () { printf("0\n"); fflush(stdout);  fork(); printf("1\n"); exit(0);}

 

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GIT-SHELL(1)                                                        Git Manual                                                        GIT-SHELL(1)

NAME
git-shell - Restricted login shell for Git-only SSH access SYNOPSIS
chsh -s $(command -v git-shell) <user> git clone <user>@localhost:/path/to/repo.git ssh <user>@localhost DESCRIPTION
This is a login shell for SSH accounts to provide restricted Git access. It permits execution only of server-side Git commands implementing the pull/push functionality, plus custom commands present in a subdirectory named git-shell-commands in the user's home directory. COMMANDS
git shell accepts the following commands after the -c option: git receive-pack <argument>, git upload-pack <argument>, git upload-archive <argument> Call the corresponding server-side command to support the client's git push, git fetch, or git archive --remote request. cvs server Imitate a CVS server. See git-cvsserver(1). If a ~/git-shell-commands directory is present, git shell will also handle other, custom commands by running "git-shell-commands/<command> <arguments>" from the user's home directory. INTERACTIVE USE
By default, the commands above can be executed only with the -c option; the shell is not interactive. If a ~/git-shell-commands directory is present, git shell can also be run interactively (with no arguments). If a help command is present in the git-shell-commands directory, it is run to provide the user with an overview of allowed actions. Then a "git> " prompt is presented at which one can enter any of the commands from the git-shell-commands directory, or exit to close the connection. Generally this mode is used as an administrative interface to allow users to list repositories they have access to, create, delete, or rename repositories, or change repository descriptions and permissions. If a no-interactive-login command exists, then it is run and the interactive shell is aborted. EXAMPLE
To disable interactive logins, displaying a greeting instead: $ chsh -s /usr/bin/git-shell $ mkdir $HOME/git-shell-commands $ cat >$HOME/git-shell-commands/no-interactive-login <<EOF #!/bin/sh printf '%s ' "Hi $USER! You've successfully authenticated, but I do not" printf '%s ' "provide interactive shell access." exit 128 EOF $ chmod +x $HOME/git-shell-commands/no-interactive-login To enable git-cvsserver access (which should generally have the no-interactive-login example above as a prerequisite, as creating the git-shell-commands directory allows interactive logins): $ cat >$HOME/git-shell-commands/cvs <<EOF if ! test $# = 1 && test "$1" = "server" then echo >&2 "git-cvsserver only handles "server"" exit 1 fi exec git cvsserver server EOF $ chmod +x $HOME/git-shell-commands/cvs SEE ALSO
ssh(1), git-daemon(1), contrib/git-shell-commands/README GIT
Part of the git(1) suite Git 2.17.1 10/05/2018 GIT-SHELL(1)
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