Standard input and output amount to pre-opened files. Usually, standard input is connected to your keyboard, and standard output is connected to your screen, but the shell lets you attach them to anything you want like this:
< redirects standard input. Any commands you run in that script, and the read builtin, will read from inputfile instead of the keyboard.
> redirects standard output. Any commands you run, and the echo builtin, will write to outputfile instead of the terminal.
So when they are telling you to read from standard input, they are telling you to just read from the default with read and feed whatever you want into it later.
You use read like
and if the first line is A B C D E, it effectively does VAR1="A"; VAR2="B" ; VAR3="C" ; VAR4="D E"
And 'standard output' just means 'print to the terminal with echo or whatever'.
We really can't give you a direct answer, we can give you the tools. And this should really be in the homework forum, please re-post there following the homework template.
Hi,
For one of my programs, I need to have a hashtable as in Perl. Unfortunately shell doesnt provide any variable like hash. Is there anyway/trick, I could implement a hash in shell (using shell scripts/sed/awk).
JP (2 Replies)
Dear all:
I want to write a script capable of reading specific rows and collumns of a table, into a variable.
Just imagine i have a file named table.dat which contains:
GENERAL INFORMATION
Col 1 Col2 Col3
1 1
2 2
3 3
4 4
What i want to do... (13 Replies)
Hi All,
I want to connect two tables in DB2 using shell script and then compare the contents of two tables field by field. Could any one please help me in connecting database tables using Unix and retriving data from the same.
Thanks,
Durwas (0 Replies)
Hi all,
I need to create a matrix of variable rows and columns. Right now i have 3 rows and two columns and following values.
Output something like
TypeA TypeB
TestCase1 Pass Fail
TestCase2 Pass ... (2 Replies)
I am trying to truncate a table using below script. When I ran the script it runs fine but table was not truncated and the spool is empty. I am not sure what is wrong with pl/sql block.
#!/bin/ksh
# ----------------------------------------------------------------------
#
# Created by: XXXX... (2 Replies)
Hi,
Can anyone tell me that, How to create table in Oracle database through shell script(ksh).
Table contains 3 fields,
1] Emp ID, String, primary key
2] Name, String
3] B Date, date.
Thanks in advance. (6 Replies)
Hi, unix gurnis
I need help for following requirement for writing a shell scritp.
log in to oracle database, query one table total records (select count(*) from table1), pass the return value to a file.
Thanks in advance (2 Replies)
Hi,
I'm an amateur and need your help in figuring this out. I have been asked to connect to a prod db from non-prod env., and download a table from prod db to non-prod env.
I was able to connect to the prod db and then run a simple query as below.
@@@@@@@@@@
... (7 Replies)
Discussion started by: arunpvp
7 Replies
LEARN ABOUT LINUX
script
SCRIPT(1) BSD General Commands Manual SCRIPT(1)NAME
script -- make typescript of terminal session
SYNOPSIS
script [-a] [-c COMMAND] [-e] [-f] [-q] [-t] [file]
DESCRIPTION
Script 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.
Options:
-a Append the output to file or typescript, retaining the prior contents.
-c COMMAND
Run the COMMAND rather than an interactive shell. This makes it easy for a script to capture the output of a program that behaves
differently when its stdout is not a tty.
-e Return the exit code of the child process. Uses the same format as bash termination on signal termination exit code is 128+n.
-f Flush output after each write. This is nice for telecooperation: One person does `mkfifo foo; script -f foo' and another can super-
vise real-time what is being done using `cat foo'.
-q Be quiet.
-t Output timing data to standard error. This data contains two fields, separated by a space. The first field indicates how much time
elapsed since the previous output. The second field indicates how many characters were output this time. This information can be used
to replay typescripts with realistic typing and output delays.
The script ends when the forked shell 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. Script works best with commands that do not manipulate
the screen, the results are meant to emulate a hardcopy terminal.
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), scriptreplay(1).
HISTORY
The script command appeared in 3.0BSD.
BUGS
Script places everything in the log file, including linefeeds and backspaces. This is not what the naive user expects.
AVAILABILITY
The script command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
Linux July 30, 2000 Linux