Hi again Now I want to make a program that will execute the programs with exec, asking the user if he wants the program to run in background or foreground.
Code:
scanf("%c",&caracter);
if (caracter=='y'){
printf("Has decidido ejecutarlo en background\n");
if((pid=fork())==0) {// fork para ejecutar en bg
for (i=1; i<argc; i++)
execl(argv[i],argv[i], 0);
exit(0);
}
}
else {
printf("Has decidido ejecutarlo en foreground\n");
for (i=1; i<argc; i++)
execl(argv[i],argv[i], 0);
}
Problem is, it will only execute 1 program. If i try to write ./execute /bin/ls /bin/ls only once will be shown. What's worse, when I try to debug it with ddd, ddd will also crash with a segmentation fault (this happens on foreground code).
Edit: related topics below my post may have given me the answer: is it because when you call exec(), the code of my program won't execute any more?
Last edited by lamachejo; 12-12-2011 at 10:39 AM..
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Discussion started by: demis87
2 Replies
LEARN ABOUT REDHAT
smrsh
SMRSH(8) System Manager's Manual SMRSH(8)NAME
smrsh - restricted shell for sendmail
SYNOPSIS
smrsh -c command
DESCRIPTION
The smrsh program is intended as a replacement for sh for use in the ``prog'' mailer in sendmail(8) configuration files. It sharply limits
the commands that can be run using the ``|program'' syntax of sendmail in order to improve the over all security of your system. Briefly,
even if a ``bad guy'' can get sendmail to run a program without going through an alias or forward file, smrsh limits the set of programs
that he or she can execute.
Briefly, smrsh limits programs to be in a single directory, by default /etc/smrsh, allowing the system administrator to choose the set of
acceptable commands, and to the shell builtin commands ``exec'', ``exit'', and ``echo''. It also rejects any commands with the characters
``', `<', `>', `;', `$', `(', `)', `
' (carriage return), or `
' (newline) on the command line to prevent ``end run'' attacks. It allows
``||'' and ``&&'' to enable commands like: ``"|exec /usr/local/bin/procmail -f- /etc/procmailrcs/user || exit 75"''
Initial pathnames on programs are stripped, so forwarding to ``/usr/ucb/vacation'', ``/usr/bin/vacation'', ``/home/server/mydir/bin/vaca-
tion'', and ``vacation'' all actually forward to ``/etc/smrsh/vacation''.
System administrators should be conservative about populating the /etc/smrsh directory. Reasonable additions are vacation(1), procmail(1),
and the like. No matter how brow-beaten you may be, never include any shell or shell-like program (such as perl(1)) in the /etc/smrsh
directory. Note that this does not restrict the use of shell or perl scripts in the sm.bin directory (using the ``#!'' syntax); it simply
disallows execution of arbitrary programs.
FILES
/etc/smrsh - directory for restricted programs
SEE ALSO sendmail(8)
$Date: 2002/04/25 13:33:40 $ SMRSH(8)
12-12-2011
Now I want to make a program that will execute the programs with exec, asking the user if he wants the program to run in background or foreground.