prog2: I understand that there are three parameters that need to be passed($1, $2p, $3), but I don't know what they are. I assume one is a file name and another is a command, but I am not sure what the third is.
That's a start.
Then you need to know how the sed command works: after the options (here: -n) the next word is the sed code. Usually one puts quotes around it, to make it better visible (and allow spaces in it). The next word(s) is(are) input files.
Compare this information with "man sed"; it starts with a short invocation description.
You need to read more in order to understand the given sed command, and what parameters make sense.
Quote:
./prog2 1,4d Zidane
These are two arguments! Parameter $1 will become 1,4d
The eqivalent of set -x in sh-derived shells is set echo in csh-derived shells. All shells take a -x option:
Last edited by MadeInGermany; 10-21-2018 at 01:56 PM..
I notice that (Mandrake) Linux and Windows do not seem to operate alike in terms of installing third party software.
Windows, on one hand, creates icons and adds items to the Start Menu, with the help of the InstallShield--or equivalent, of course, but Linux, on the other hand, seems to care... (3 Replies)
I have installed Red Hat Linux 9.0 recently on my computer.
Im wondering if there are any good sites for downloading linux programs besides the site of Red Hat.
Thank you in advance!:D (4 Replies)
I need help to create batch file .
I want to run some programs in sequence in batch mode . I have one file which contains the name of program and command
The test.bat file contain this data
stsrun -v devel area1.exp
stsrun -v devel prime1.exp
stsrun -v devel treat.exp
Please help... (1 Reply)
:cool:
I need to execute a shell script to do the following:
cat a file
run two back ground processes using the first two values from the file
wait till those background processes finish
run two more background processes using the next two values from the file
wait till those background... (1 Reply)
Hi,
I want to make changes to inittab file and reread it using "telinit q" to make changes effective immediately. Is it safe to do that while important apps are running ?
thanks
Vilius (1 Reply)
Are the programs written on schedulers ,thread library , process management, memory management, et al called systems programs ? How are they different from the programs that implement functions like open() , printf() , scanf() , read() .. they have a prefix sys_open, sys_close, sys_read etc , right... (1 Reply)
Hello.
The last days I extended an open-source C++ library by some faster functions. This library provides a lot of short test programs which guarantee that the library works exactly.
The compilation of each test works in a Makefile automatically.
What I need is a shell script which... (5 Replies)
Hey guys,
Suppose i run passwd via bash shell. It is a suid program, which temporarily runs as root(owner) and modifies the user entries.
However, when i write a C file and give 4755 permission and root ownership to the 'a.out' file , it doesn't run as root in bash shell. I verified this by... (2 Replies)
Discussion started by: syncmaster
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)