Gurus,
I am teaching myself C and have a question.
I wrote a small prog that reads characters as entered at the prompt and checks the value for EOF.
Unless I am 100% wrong, the value will be '1' until getchar() has anything to read in my stream.
/* PROG 1 */
#include <stdio.h>
... (4 Replies)
#!/usr/bin/perl
open(STDOUT, ">>$Textfile")
open(STDERR, ">>$Textfile")
print "program running\n";
$final = join("+", $initial,$final) #5
close (STDOUT);
close (STDERR);Hi all, above is my perl code. Notice i have captured the stdout and stderr to the same textfile. my code is expected to... (1 Reply)
Hi,
I am re-writing a script I wrote which emulated the "rm" command, in my orginal script I had problems with precedence, I did find a way round it by creating a seperate case statements which checked the options and performed the actions accordingly, does anyone know if I can use getopts... (1 Reply)
Hi All,
I have created a common makefile that compiles both pc and c files.
i have created the dependency between the files as
.pc.o:
-----------
.c.o:
-----------
I will be deleting the .c files created from the .pc files, once the object file is created. ( better storage... (7 Replies)
I really don't know the meaning of these operators. Could someone explain the meanings so I can make my test for today?
<, <=, ==, !=, >=, >,
||, &&, ! ~ , !~
Thanks! (1 Reply)
Hi,
shell is /bin/ksh
I am trying to do the following in my code.. but its showing me an error
if ] && ] ]]; then
echo "id is $ida and chk_dy is $chk_dy"
fi
the error I get is
syntax error at line 23 : `"$ida"' unexpected
I need to execute the... (2 Replies)
Hi All,
I am new to unix.
In this forum some days back, I have read something like below:
1) Do not use perl if awk can do your work.
2) Do not use awk if sed can do your work.
.
.
.
I do not re-collect the whole thing. I think it is good to know the precedence of using these... (2 Replies)
Discussion started by: Prathmesh
2 Replies
LEARN ABOUT OPENDARWIN
su
SU(1) BSD General Commands Manual SU(1)NAME
su -- substitute user identity
SYNOPSIS
su [-flm] [login] [-c shell arguments]
DESCRIPTION
su requests the password for login and switches to that user and group ID after obtaining proper authentication. A shell is then executed,
and any additional shell arguments after the login name are passed to the shell. If su is executed by root, no password is requested and a
shell with the appropriate user ID is executed.
The options are as follows:
-c Invoke the following command in a subshell as the specified user.
-f If the invoked shell is csh(1), this option prevents it from reading the ``.cshrc'' file.
-l Simulate a full login. The environment is discarded except for HOME, SHELL, PATH, TERM, and USER. HOME and SHELL are modified as
above. USER is set to the target login. PATH is set to ``/bin:/usr/bin''. TERM is imported from your current environment. The
invoked shell is the target login's, and su will change directory to the target login's home directory. This option is identical to
just passing "-", as in "su -".
-m Leave the environment unmodified. The invoked shell is your login shell, and no directory changes are made. As a security precau-
tion, if the target user's shell is a non-standard shell (as defined by getusershell(3)) and the caller's real uid is non-zero, su
will fail.
The -l and -m options are mutually exclusive; the last one specified overrides any previous ones.
Only users in group ``wheel'' (normally gid 0) or group ``admin'' (normally gid 20) can su to ``root''.
By default (unless the prompt is reset by a startup file) the super-user prompt is set to ``#'' to remind one of its awesome power.
SEE ALSO csh(1), login(1), sh(1), skey(1), kinit(1), kerberos(1), passwd(5), group(5), environ(7)ENVIRONMENT
Environment variables used by su :
HOME Default home directory of real user ID unless modified as specified above.
PATH Default search path of real user ID unless modified as specified above.
TERM Provides terminal type which may be retained for the substituted user ID.
USER The user ID is always the effective ID (the target user ID) after an su unless the user ID is 0 (root).
HISTORY
A su command appeared in Version 7 AT&T UNIX.
BSD April 18, 1994 BSD