10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
hi all,
need a script or command to get the previous date for the given input date...
like in my script i will pass date as input parameter like 2014-12-01 and i want the output as previous date.. ie.. 2014-11-30 (2 Replies)
Discussion started by: hemanthsaikumar
2 Replies
2. Shell Programming and Scripting
hi all
i'm new in shell scripting and now i'm working on project and i wanna make a function take input from user and test it's datatype then if correct write it to file
i wounder what is the best way to do this ?
can i use awk ?
edit by bakunin: Please give your threads a meaningful... (5 Replies)
Discussion started by: mohamed91
5 Replies
3. Shell Programming and Scripting
Hi,
I need to get input arguments, as well as validate them. This is how I'm reading them:
#!/bin/bash
args="$@" # save arguments to variable
## Read input arguments, if so
while ; do
case $1 in
-v | --verbose ) verbose=true;;
-z | --gzip ) compression="gz";;
... (3 Replies)
Discussion started by: AlbertGM
3 Replies
4. Shell Programming and Scripting
Hi,
I have been trying to get the yesterdays date for the Input date I pass.
I know how to do for the current timestamp but how to do for the input date.
Is there any way I can convert to epoch time and do manipulations and back to human readable date?
Please help
Thanks
... (1 Reply)
Discussion started by: abhi1988sri
1 Replies
5. Shell Programming and Scripting
Hello,
I have a file like this:
2012112920121130
12345620121130msABowwiqiq
34477420121129amABamauee
e7748420121130ehABeheheei
in case the content of the file has the date of yesterday within the lines containing pattern AB this should be replaced by the current date. But if I use... (3 Replies)
Discussion started by: Lilu_CK
3 Replies
6. UNIX for Dummies Questions & Answers
This may be a dumb question, but googling is not giving me an answer. I'm trying to figure out how to refer to an input file in my code.
Lets say i run a script in bash:
"sh shellscript.sh inputfile"
(Inputfile will be variable...whatever file i run the script on)
I wanted to make... (5 Replies)
Discussion started by: legato22
5 Replies
7. UNIX for Advanced & Expert Users
Hello,
I'm having problem with an iptables rule. It seems that on one of two systems on the nat table, the INPUT chain doesn't exist for some strange reason.
I get the error below:
# iptables -t nat -A INPUT -j ACCEPT
iptables: No chain/target/match by that name.
Here is my kernel on... (0 Replies)
Discussion started by: Narnie
0 Replies
8. Shell Programming and Scripting
Ok, I have a script with a commandline option that allows the user to add a custom function to the script file. I have tried everything in my limited knowledge of sed to get this to work and keep coming up short. I need sed to search for a line starting with a pattern, I've got that part so far,... (0 Replies)
Discussion started by: DC Slick
0 Replies
9. UNIX for Dummies Questions & Answers
Hi,
I want to check a particular word is in standard error output or not. Can I acheive it in single command?
For example,
Delete file_name 2>error.log
cat error.log
Output:
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
Successfully deleted
XXXXXXXXXXXXXXXXX
where delete is... (2 Replies)
Discussion started by: poova
2 Replies
10. Shell Programming and Scripting
Hi Experts,
I have files name
report_20090416
report_20090417
report_20090418
report_20090420
report_20090421
I have 2 input from user
From Date: 20090417
To Date: 20090420
and I need to grep only those line in between. Output should be
report_20090417
report_20090418... (3 Replies)
Discussion started by: tanit
3 Replies
rc(1M) rc(1M)
NAME
rc - general purpose sequencer invoked upon entering new run level
SYNOPSIS
DESCRIPTION
The shell script is the general sequencer invoked upon entering a new run level via the command (where N equals 0-6). The script is typi-
cally invoked by the corresponding entry in the file as follows:
is the startup and shutdown sequencer script. There is only one sequencer script and it handles all of the sequencer directories. This
script sequences the scripts in the appropriate sequencer directories in alphabetical order as defined by the shell and invokes them as
either startup or kill scripts.
If a transition from a lower to a higher run level (i.e., init state) occurs, the start scripts for the new run level and all intermediate
levels between the old and new level are executed. If a transition from a higher to a lower run level occurs, the kill scripts for the new
run level and all intermediate levels between the old and new level are executed.
If a start script link (e.g., in sequencer N has a stop action, the corresponding kill script should be placed in sequencer (e.g., Actions
started in level N should be stopped in level This way, a system shutdown (e.g., transition from level 3 directly to level 0) will result
in all subsystems being stopped.
Start and Kill Scripts
In many cases, a startup script will have both a start and a kill action. For example, the inetd script starts the Internet daemon in the
start case, and kills that process in the stop case. Instead of two separate scripts, only one exists, which accepts both the and argu-
ments and executes the correct code. In some cases, only a start action will be applicable. If this is the case, and if the action is
specified, the script should produce a usage message and exit with an error. In general, scripts should look at their arguments and pro-
duce error messages if bad arguments are present. When a script executes properly, it must exit with a return value of zero. If an error
condition exists, the return value must be nonzero.
Naming Conventions
The startup and shutdown scripts (referred to as startup scripts hereafter) exist in the directory, named after the subsystem they control.
For example, the script controls starting up the daemon. The contents of sequencer directories consist of symbolic links to startup
scripts in These symbolic links must follow a strict naming convention, as noted in the various fields of this example:
where the fields are defined as follows:
The sequencer directory is numbered to reflect the
run level for which its contents will be executed. In this case, start scripts in this directory will be executed
upon entering run level 2 from run level 1, and kill scripts will be executed upon entering run level 2 from run
level 3.
The first character of a sequencer link name determines
whether the script is executed as a start script (if the character is or as a kill script (if the character is
A three digit number is used for sequencing scripts within
the sequencer directory. Scripts are executed by type (start or kill) in alphabetical order as defined by the shell.
Although it is not recommended, two scripts may share the same sequence number.
The name of the startup script follows the sequence number.
The startup script name must be the same name as the script to which this sequencer entry is linked. In this exam-
ple, the link points to
Note that short file name systems require file names of 14 or less characters. This means that the fourth field is
limited to 10 or fewer characters.
Scripts are executed in alphabetical order. The entire file name of the script is used for alphabetical ordering
purposes.
When ordering start and kill script links, note that subsystems started in any given order should be stopped in the
reverse order to eliminate any dependencies between subsystems. This means that kill scripts will generally not have
the same numbers as their start script counterparts. For example, if two subsystems must be started in a given order
due to dependencies (e.g., followed by the kill counterparts to these scripts must be numbered so that the subsystems
are stopped in the opposite order in which they were started (e.g., followed by
Also keep in mind that kill scripts for a start script in directory will reside in For example, and might be
start/kill counterparts.
Arguments
The startup/shutdown scripts should be able to recognize the following four arguments (where applicable):
The argument is passed to scripts whose names start with Upon receiving the argument, the script should perform its start
actions.
The argument is passed to scripts whose names start with Upon receiving the argument, the script should perform its stop
actions.
The argument is passed to scripts whose names start with so that the script can report back a short message indicating
what the start action will do. For instance, when the spooler script is invoked with a argument, it echoes
This string is used by the startup routines. Scripts given just the argument will only print a message and not per-
form any actions.
The argument is passed to scripts whose names start with so that the script can report back a short message indicating
what the stop action will do. For instance, when the spooler script is invoked with a argument, it echoes
This string is used by the shutdown checklist. Scripts given just the argument will only print a message and not
perform any actions.
Script Output
To ensure proper reporting of startup events, startup scripts are required to comply with the following guidelines for script output.
o Status messages, such as
must be directed to stdout. All error messages must be directed to stderr.
o Script output, both stdout and stderr, is redirected to log file unless the startup checklist mode is set to the raw mode. In
this case, all output goes to the console. All error messages should be echoed to stdout or stderr.
o Startup scripts are not allowed to send messages directly to the console, or to start any daemons that immediately write to the
console. This restriction exists because these scripts are now started by the checklist wrapper. All script output should go to
either stdout or stderr, and thus be captured in a log file. Any console output will be garbled.
o When a startup script returns an exit code of can display a specific message on the console prior to rebooting the system. This
is achieved by creating a text file named containing the text to be displayed to the console. Note that deletes this file after
displaying the message, so startup scripts need to write this file each time a specific message is required to be displayed on
console prior to reboot.
RETURN VALUE
The return values for startup scripts are as follows:
Script exited without error.
Script encountered errors.
Script was skipped due to overriding control variables
from files, or for other reasons, and did not actually do anything.
Script will automatically reboot the system.
Script exited without error and started a process in background mode.
For return values greater than
the action is same as return value script encountered errors.
SEE ALSO
init(1M), shutdown(1M), inittab(4), rc.config(4).
rc(1M)