12-16-2004
Just for info, newer shells like bash and ksh allow more "usual" short circuit operator syntax of && and || so you can do things like
[[ -d file1 && -d file2 ]] || echo "Both files are not directories"
i.e. with && for AND, || for OR
Cheers
ZB
This User Gave Thanks to zazzybob For This Post:
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi,
I have a statement in shell script which i am writing below:
if ]
then
.....
What is the meaning of -a option in files, meaning of the statement in the if condition ] means.
Thanks (3 Replies)
Discussion started by: dreams5617
3 Replies
2. Shell Programming and Scripting
can someone please tell me what is wrong with the below. i'm trying to get a script to run if the content of a variable is either small letter y or capital letter Y.
if
then
whatever
fi (4 Replies)
Discussion started by: Terrible
4 Replies
3. Shell Programming and Scripting
I want to write a program that would convert yard to feet and feet to yard.
i.e
1 yard = 3 * feet
Echo "enter a"
read a
expr a *3
The trick is that I want to give the user some options. After the conversion from yard to feet is done, I want to ask the user whether or not he/she wants to... (10 Replies)
Discussion started by: Ernst
10 Replies
4. Shell Programming and Scripting
In my ksh script, if the conditions of a if statement are true, then do nothing; otherwise, execute some commands.
How do I write the "do nothing" statement in the following example?
Example:
if (( "$x"="1" && "$y"="a" && "$z"="happy" ))
then
do nothing
else
command
command
fi... (3 Replies)
Discussion started by: april
3 Replies
5. Shell Programming and Scripting
Hi All,
I am using Unix ksh script.
I need to insert values to a table using the o/p from a slelect statement.
Can anybody Help!
My script looks like tihs.
---`sqlplus -s username/password@SID << EOF
set heading off
set feedback off
set pages 0
insert into ${TB_NAME}_D... (2 Replies)
Discussion started by: nkosaraju
2 Replies
6. UNIX for Dummies Questions & Answers
I have the program:
#!/bin/ksh
echo Please enter yes or no
read n
typeset -l n
if ]
then
echo My name
exit
else
echo delete my name
fi
Question:
How can I make the program accept only the word "yes" or "no" otherwise it will ask the user to re-enter?
Thanks! (7 Replies)
Discussion started by: bobo
7 Replies
7. Shell Programming and Scripting
I'm trying to create a script that would allow me to identify the sucessful removal of a file. Here's what i put together so far, let me know if it's correct or not.
FILE_NAME="cactus.dat"
FILE_FIND='find / -name $FILE_NAME'
if ;then
echo "cactus.dat was not removed successfully" ... (3 Replies)
Discussion started by: sdpinoy
3 Replies
8. Shell Programming and Scripting
${PFILE}.backupfile
Please tell me what the above statement means? (1 Reply)
Discussion started by: lg123
1 Replies
9. Shell Programming and Scripting
Hi,
I have this code here. Its suppose to do something when certain condition is met, I'm pretty sure at least one of the condition will be meet somewhere in the loop but it always go to else part of the script.
Is something wrong on this script?
age_list=`tar -tvf /home/dir/$tarfile... (4 Replies)
Discussion started by: erin00
4 Replies
10. Shell Programming and Scripting
Hi folks,
I have a scenario to convert the update statements into insert statements using shell script (awk, sed...) or in database using regex.
I have a bunch of update statements with all columns in a file which I need to convert into insert statements.
UPDATE TABLE_A SET COL1=1 WHERE... (0 Replies)
Discussion started by: dev123
0 Replies
DIFF(1) General Commands Manual DIFF(1)
NAME
diff - differential file comparator
SYNOPSIS
diff [ -efbh ] file1 file2
DESCRIPTION
Diff tells what lines must be changed in two files to bring them into agreement. If file1 (file2) is `-', the standard input is used. If
file1 (file2) is a directory, then a file in that directory whose file-name is the same as the file-name of file2 (file1) is used. The
normal output contains lines of these forms:
n1 a n3,n4
n1,n2 d n3
n1,n2 c n3,n4
These lines resemble ed commands to convert file1 into file2. The numbers after the letters pertain to file2. In fact, by exchanging `a'
for `d' and reading backward one may ascertain equally how to convert file2 into file1. As in ed, identical pairs where n1 = n2 or n3 = n4
are abbreviated as a single number.
Following each of these lines come all the lines that are affected in the first file flagged by `<', then all the lines that are affected
in the second file flagged by `>'.
The -b option causes trailing blanks (spaces and tabs) to be ignored and other strings of blanks to compare equal.
The -e option produces a script of a, c and d commands for the editor ed, which will recreate file2 from file1. The -f option produces a
similar script, not useful with ed, in the opposite order. In connection with -e, the following shell program may help maintain multiple
versions of a file. Only an ancestral file ($1) and a chain of version-to-version ed scripts ($2,$3,...) made by diff need be on hand. A
`latest version' appears on the standard output.
(shift; cat $*; echo '1,$p') | ed - $1
Except in rare circumstances, diff finds a smallest sufficient set of file differences.
Option -h does a fast, half-hearted job. It works only when changed stretches are short and well separated, but does work on files of
unlimited length. Options -e and -f are unavailable with -h.
FILES
/tmp/d?????
/usr/lib/diffh for -h
SEE ALSO
cmp(1), comm(1), ed(1)
DIAGNOSTICS
Exit status is 0 for no differences, 1 for some, 2 for trouble.
BUGS
Editing scripts produced under the -e or -f option are naive about creating lines consisting of a single `.'.
DIFF(1)