I am using the command below to send emails to users using a for loop. If The command finds the user Id in 1st column then it will print the email Id of the user from the 2nd column.
This command is getting executed when I give the username directly or execute it manually in command line. But when I try to use the same code in shell script to process various usernames in a for loop, the awk command doesn't recognize the variables
The code I am using in shell script is below. Can someone please let me know how to fix this?
Code:
For usr in ${users[@]}; do
/usr/bin/awk -F "," ' $1 == "$usr" {print $2}' file.csv
done > out.txt
Hi,
I have a situation where I have to specify a different value to an awk command, I beleive i have the gist of this done, however I am not able to get this correct. Here is what I have so far
echo $id
065859555
This value occurs in a "pipe" delimited file in postition 8. Hence I would... (1 Reply)
I'm writing a bash script, and I am having trouble with this line:
awk '{print "url = \"http://www.example.com/directory/$type/"$1"\""}' input.file > output.file
Within the URL being printed, I wish the value of the variable "$type" to be printed, after being read from user input from the... (2 Replies)
I have a log file that has certain fields that I want to evaluate, and depending on the value in those fields, I want to put the value of a different field in that line in a particular variable that I'll use later on down the log file. Sort of like setting a switch to change what I do with a bunch... (5 Replies)
I am writing a script where I need awk to test if two columns are the same and shell to do something if they are or are not.
Here is the code I'm working with:
@ test = 0
...
test = `awk '{if($1!=$2) print 1; else print 0}' time_test.tmp`
#time_test.tmp holds two values separated by a space... (3 Replies)
Hello,
I extracted a list of files in a directory with the command ls . However this is not my computer, so the ls functionality has been revamped so that it gives the filesizes in front like this :
This is the output of ls command : I stored the output in a file filelist
1.1M... (5 Replies)
Hi all,
My oracle procedure returns more than one value.
i need to get one value at a time upto ending value ina shell script.
Please help me..... (9 Replies)
Hy!
I need to post-process some data files which have variable (and periodic) number of fields. For example, I need to square (data -> data*data) the folowing data file: -5.34281E-28 -3.69822E-29 8.19128E-29 9.55444E-29 8.16494E-29 6.23125E-29
4.42106E-29 2.94592E-29 1.84841E-29 ... (5 Replies)
Hello all,
I have a txt file containing millions of lines. Below is the example:
{tx:be} head -50 file.txt
Instr1: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Instr1:... (6 Replies)
Hi Gurus,
I have a script which assign awk output to shell variable. current it uses two awk command to assign value to two variables. I want to use one command to assign two values to two variables. I tried the code, but it does't work. kindly provide your suggestion.
current code... (2 Replies)
Discussion started by: green_k
2 Replies
LEARN ABOUT X11R4
su
SU(1) User Commands SU(1)NAME
su - change user ID or become superuser
SYNOPSIS
su [options] [username]
DESCRIPTION
The su command is used to become another user during a login session. Invoked without a username, su defaults to becoming the superuser.
The optional argument - may be used to provide an environment similar to what the user would expect had the user logged in directly.
Additional arguments may be provided after the username, in which case they are supplied to the user's login shell. In particular, an
argument of -c will cause the next argument to be treated as a command by most command interpreters. The command will be executed by the
shell specified in /etc/passwd for the target user.
You can use the -- argument to separate su options from the arguments supplied to the shell.
The user will be prompted for a password, if appropriate. Invalid passwords will produce an error message. All attempts, both valid and
invalid, are logged to detect abuse of the system.
The current environment is passed to the new shell. The value of $PATH is reset to /bin:/usr/bin for normal users, or
/sbin:/bin:/usr/sbin:/usr/bin for the superuser. This may be changed with the ENV_PATH and ENV_SUPATH definitions in /etc/login.defs.
A subsystem login is indicated by the presence of a "*" as the first character of the login shell. The given home directory will be used as
the root of a new file system which the user is actually logged into.
OPTIONS
The options which apply to the su command are:
-c, --command COMMAND
Specify a command that will be invoked by the shell using its -c.
The executed command will have no controlling terminal. This option cannot be used to execute interactive programs which need a
controlling TTY.
-, -l, --login
Provide an environment similar to what the user would expect had the user logged in directly.
When - is used, it must be specified before any username. For portability it is recommended to use it as last option, before any
username. The other forms (-l and --login) do not have this restriction.
-s, --shell SHELL
The shell that will be invoked.
The invoked shell is chosen from (highest priority first):
The shell specified with --shell.
If --preserve-environment is used, the shell specified by the $SHELL environment variable.
The shell indicated in the /etc/passwd entry for the target user.
/bin/sh if a shell could not be found by any above method.
If the target user has a restricted shell (i.e. the shell field of this user's entry in /etc/passwd is not listed in /etc/shells), then
the --shell option or the $SHELL environment variable won't be taken into account, unless su is called by root.
-m, -p, --preserve-environment
Preserve the current environment, except for:
$PATH
reset according to the /etc/login.defs options ENV_PATH or ENV_SUPATH (see below);
$IFS
reset to "<space><tab><newline>", if it was set.
If the target user has a restricted shell, this option has no effect (unless su is called by root).
Note that the default behavior for the environment is the following:
The $HOME, $SHELL, $USER, $LOGNAME, $PATH, and $IFS environment variables are reset.
If --login is not used, the environment is copied, except for the variables above.
If --login is used, the $TERM, $COLORTERM, $DISPLAY, and $XAUTHORITY environment variables are copied if they were set.
Other environments might be set by PAM modules.
CAVEATS
This version of su has many compilation options, only some of which may be in use at any particular site.
CONFIGURATION
The following configuration variables in /etc/login.defs change the behavior of this tool:
CONSOLE_GROUPS (string)
List of groups to add to the user's supplementary groups set when logging in on the console (as determined by the CONSOLE setting).
Default is none.
Use with caution - it is possible for users to gain permanent access to these groups, even when not logged in on the console.
DEFAULT_HOME (boolean)
Indicate if login is allowed if we can't cd to the home directory. Default is no.
If set to yes, the user will login in the root (/) directory if it is not possible to cd to her home directory.
ENV_PATH (string)
If set, it will be used to define the PATH environment variable when a regular user login. The value is a colon separated list of paths
(for example /bin:/usr/bin) and can be preceded by PATH=. The default value is PATH=/bin:/usr/bin.
ENV_SUPATH (string)
If set, it will be used to define the PATH environment variable when the superuser login. The value is a colon separated list of paths
(for example /sbin:/bin:/usr/sbin:/usr/bin) and can be preceded by PATH=. The default value is PATH=/sbin:/bin:/usr/sbin:/usr/bin.
SULOG_FILE (string)
If defined, all su activity is logged to this file.
SU_NAME (string)
If defined, the command name to display when running "su -". For example, if this is defined as "su" then a "ps" will display the
command is "-su". If not defined, then "ps" would display the name of the shell actually being run, e.g. something like "-sh".
SYSLOG_SU_ENAB (boolean)
Enable "syslog" logging of su activity - in addition to sulog file logging.
FILES
/etc/passwd
User account information.
/etc/shadow
Secure user account information.
/etc/login.defs
Shadow password suite configuration.
EXIT VALUES
On success, su returns the exit value of the command it executed.
If this command was terminated by a signal, su returns the number of this signal plus 128.
If su has to kill the command (because it was asked to terminate, and the command did not terminate in time), su returns 255.
Some exit values from su are independent from the executed command:
0
success (--help only)
1
System or authentication failure
126
The requested command was not found
127
The requested command could not be executed
SEE ALSO login(1), login.defs(5), sg(1), sh(1).
shadow-utils 4.5 01/25/2018 SU(1)
04-29-2020
