Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: How to check for Input Redirection in my script?
Top Forums Shell Programming and Scripting How to check for Input Redirection in my script? Post 302408457 by bharath.gct on Monday 29th of March 2010 02:30:55 PM
Old 03-29-2010
Thanks kshji,

I did try that, below is the example where I tried to use the No. of arguments to find the redirection, but that does NOT work for me. And only so I did not post it in my first post.

my.script
Code:
#! /bin/ksh
numargs=$#
case $numargs in
0)
  echo "No. of Args : $numargs"
  echo "Parameter 0 = $0"
;;
*)
  echo "No. of Args : $numargs"
  i=1;
  for d in $@
  do
    echo "Parameter $i = `echo $d`"
    i=`expr $i + 1`
  done
;;
esac

Below are the different runs:
Run 1: Running with NO redirection

Code:
$ ./my.script
No. of Args : 0
Parameter 0 = ./my.script

Run 2: Running with redirection
Code:
$ ./my.script < test.file
No. of Args : 0
Parameter 0 = ./my.script

Run 3: Running with arguments
Code:
$ ./my.script Hi this is a test text
No. of Args : 6
Parameter 1 = Hi
Parameter 2 = this
Parameter 3 = is
Parameter 4 = a
Parameter 5 = test
Parameter 6 = text

Hope this helps! Let me know if you need any more information.

Thanks
Bharath
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Input Redirection

Hi everybody, first of all i am a new member in UNIX.com and this is my first post. I am impressed with the amount of information a person can ever have in this forum, it is really great having something similiar; anyways let me tell you about the problem I am having, hope you will answer me.... (6 Replies)
Discussion started by: majeed73
6 Replies

2. Shell Programming and Scripting

input redirection question

Hi, in my script I need to execute the following command: query $id 456 432 but it waits for a RETURN character from keyboard and therefore, it fails. I tried something like: query $id 456 432 << '\n' but, i'ts clear it is not correct. Is there any way to do this? Thxs. (0 Replies)
Discussion started by: luistid
0 Replies

3. Shell Programming and Scripting

Asking about shell script input output redirection

Hi, Can anyone please tell me what these lines do? ls >& outfile ls outfile 2>&1 Thanks. (1 Reply)
Discussion started by: trivektor
1 Replies

4. Shell Programming and Scripting

permanent redirection of standard input

while running a user inter-active program how can we get the commands from a file instead of the user? is there anyway to permanently redirect content of a file to standard input? (6 Replies)
Discussion started by: gfhgfnhhn
6 Replies

5. Shell Programming and Scripting

Input redirection and for loop

Hello, I need help with a bash script that I try to improve. I could not find answer so far, maybe because I'm not to familiar with the terminology so feel free to correct my language. I have a script that looks like: NODES="node_a node_b node_c" for NODE in $NODES do ... (4 Replies)
Discussion started by: pn8830
4 Replies

6. Shell Programming and Scripting

Read input and output redirection filename within a script

Hello everyone, My requirement is that within a script I need to construct the command line exactly that it was invoked with. For example : sh a.sh arg1 arg2 arg3 < input.txt > output.txt Now within a.sh, I construct a file which has these contents " sh a.sh arg1 arg2 arg3 < input.txt >... (8 Replies)
Discussion started by: hedonist12
8 Replies

7. Shell Programming and Scripting

How to check the user input to be valid using shell script?

How to check the user input to be valid using shell script? The valid input is in the format like as follows. 1. It can only have r,w,x or a hyphen and nothing else. 2. ensure the r, w, x are in the correct order. for example: rwxr-xr-x is a valid format. Thanks (5 Replies)
Discussion started by: hyeewang
5 Replies

8. UNIX for Dummies Questions & Answers

When do I use input redirection?

Can someone please explain when input redirection is necessary? For example, "cat filename" and "cat< filename" produce the same result. I was told that if I need to bunzip a file that I should type "bunzip2<filename.bz2." However, if I omit the "<" I still get the same result. Can someone... (4 Replies)
Discussion started by: PTcharger
4 Replies

9. Shell Programming and Scripting

Input redirection script

Hi, #!/bin/bash while ; do rm -f /tmp/pipe mkfifo /tmp/pipe ./yuv4mpeg_to_v4l2 < /tmp/pipe & mplayer tom_and_jerry.mp4 -vf scale=480:360 -vo yuv4mpeg:file=/tmp/pipe sleep 65; done When I run this - after mplayer finishes playing video it says - Exiting... (End of... (2 Replies)
Discussion started by: ashokvpp
2 Replies

10. Shell Programming and Scripting

Input redirection within bash script

Hi, when I try to redirect input and the command is described as a string within an array redirection does not work. why? #!/bin/bash dir=("tail < ./hello.txt") tail < ./hello.txt #works ${dir} #does not work (2 Replies)
Discussion started by: heinzel
2 Replies

LEARN ABOUT OPENDARWIN

script

SCRIPT(1)						    BSD General Commands Manual 						 SCRIPT(1)

NAME

     script -- make typescript of terminal session

SYNOPSIS

     script [-a] [-k] [-q] [-t time] [file [command ...]]

DESCRIPTION

     The script utility makes a typescript of everything printed on your terminal.  It is useful for students who need a hardcopy record of an
     interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).

     If the argument file is given, script saves all dialogue in file.	If no file name is given, the typescript is saved in the file typescript.

     If the argument command ... is given, script will run the specified command with an optional argument vector instead of an interactive shell.

     Options:

     -a       Append the output to file or typescript, retaining the prior contents.

     -k       Log keys sent to program as well as output.

     -q       Run in quiet mode, omit the start and stop status messages.

     -t time  Specify time interval between flushing script output file.  A value of 0 causes script to flush for every character I/O event.  The
	      default interval is 30 seconds.

     The script ends when the forked shell (or command) exits (a control-D to exit the Bourne shell (sh(1)), and exit, logout or control-d (if
     ignoreeof is not set) for the C-shell, csh(1)).

     Certain interactive commands, such as vi(1), create garbage in the typescript file.  The script utility works best with commands that do not
     manipulate the screen.  The results are meant to emulate a hardcopy terminal, not an addressable one.

ENVIRONMENT

     The following environment variable is utilized by script:

     SHELL  If the variable SHELL exists, the shell forked by script will be that shell.  If SHELL is not set, the Bourne shell is assumed.  (Most
	    shells set this variable automatically).

SEE ALSO

     csh(1) (for the history mechanism).

HISTORY

     The script command appeared in 3.0BSD.

BUGS

     The script utility places everything in the log file, including linefeeds and backspaces.	This is not what the naive user expects.

     It is not possible to specify a command without also naming the script file because of argument parsing compatibility issues.

     When running in -k mode, echo cancelling is far from ideal.  The slave terminal mode is checked for ECHO mode to check when to avoid manual
     echo logging.  This does not work when in a raw mode where the program being run is doing manual echo.

BSD
								   June 6, 1993 							       BSD
All times are GMT -4. The time now is 01:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy