I came across the following program:
What is the usage of let statement? I have never come across the same. Please let me know the usage, syntax and the need.
Instead of using the let statement above, we could have directly used
Then what is the need of using "let" here or anywhere else?
Last edited by Scott; 01-27-2010 at 09:05 PM..
Reason: Please use code tags
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)
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)
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)
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)
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)
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)
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 $FILE_NAME'
if ;then
echo "cactus.dat was not removed successfully" ... (3 Replies)
Hi,
I have this code here. Its suppose to do something when certain condition is met, I'm pretty sure at least one of the condition will be meet somewhere in the loop but it always go to else part of the script.
Is something wrong on this script?
age_list=`tar -tvf /home/dir/$tarfile... (4 Replies)
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
LEARN ABOUT PLAN9
test
TEST(1) General Commands Manual TEST(1)NAME
test - set status according to condition
SYNOPSIS
test expr
DESCRIPTION
Test evaluates the expression expr. If the value is true the exit status is null; otherwise the exit status is non-null. If there are no
arguments the exit status is non-null.
The following primitives are used to construct expr.
-r file True if the file exists (is accessible) and is readable.
-w file True if the file exists and is writable.
-x file True if the file exists and has execute permission.
-e file True if the file exists.
-f file True if the file exists and is a plain file.
-d file True if the file exists and is a directory.
-s file True if the file exists and has a size greater than zero.
-t fildes True if the open file whose file descriptor number is fildes (1 by default) is the same file as /dev/cons.
s1 = s2 True if the strings s1 and s2 are identical.
s1 != s2 True if the strings s1 and s2 are not identical.
s1 True if s1 is not the null string. (Deprecated.)
-n s1 True if the length of string s1 is non-zero.
-z s1 True if the length of string s1 is zero.
n1 -eq n2 True if the integers n1 and n2 are arithmetically equal. Any of the comparisons -ne, -gt, -ge, -lt, or -le may be used in place
of -eq. The (nonstandard) construct -l string, meaning the length of string, may be used in place of an integer.
These primaries may be combined with the following operators:
! unary negation operator
-o binary or operator
-a binary and operator; higher precedence than -o
( expr ) parentheses for grouping.
The primitives -b, -u, -g, and -s return false; they are recognized for compatibility with POSIX.
Notice that all the operators and flags are separate arguments to test. Notice also that parentheses and equal signs are meaningful to rc
and must be enclosed in quotes.
EXAMPLES
Test is a dubious way to check for specific character strings: it uses a process to do what an rc(1) match or switch statement can do. The
first example is not only inefficient but wrong, because test understands the purported string "-c" as an option.
if (test $1 '=' "-c") echo OK # wrong!
A better way is
if (~ $1 -c) echo OK
Test whether is in the current directory.
test -f abc -o -d abc
SOURCE
/sys/src/cmd/test.c
SEE ALSO rc(1)TEST(1)