if tests the exit status of [. In the "if" branch, by definition, $? will be 0. It is the exit code of the command [ -s temp.txt ]. Yes, it is confusing to newbies that "open square bracket" is the name of a command, but that's what it is. You can call it test if you think that's less confusing.
Hi friends, :)
In a shell script i found the following if condition.
echo -n "Which version of $1 do you want to restore ('0' to quit)? : "
read desired
if ${desired:=1} -ge $index ] ; then
echo "$0: Restore canceled by user: index value too big." >&2
exit 1
fi
Can... (1 Reply)
i have a paramter data_date in which i am passing a string value.i want to find out another paramter file_date from this.the logic is given below
if day of data_date = sunday or monday
then
file_date=data_date-1
else
file_date=data_date-2
i am passing data_date as 20061027.
how can i... (3 Replies)
Hi,
I am trying to execute this command, but is it not working, says "`;' unexpected"
eval $lgrep $SAM_CMD ; if ; then ; echo "No Error" ; fi
What i want is, return the command output, if it is non zero, say "No Error".
Thanks, John. (21 Replies)
Executed the following if conditions .. and got different results .
only (( )) gave correct o/p with all scenarios .
Can anybody please let me know what is the difference between and ] and ((condition)) when used with if condition.
And why each condition gave different result.
1.... (2 Replies)
hi,
I have some problems in my simple script about the redirect echo stdout command inside a condition. Why is the echo command inside the elif still execute in the else command
Here are my simple script
After check on the two diff output the echo stdout redirect is present in two diff... (3 Replies)
HI
My doubt may be basic one but I need to get it clarified..
When i use "if" condition that checks for many AND, OR logical conditions
like
if ]; then
return 0
fi
Even the if condition fails it returns as zero.. Any clue..
But if i add else condition like
if ]; ... (2 Replies)
Hi all
Unix newbie - please be gentle
Am modifying an existing script to error trap a variable with a length of 0
#!/bin/bash
ipfile='/var/data/bin/ipaddress'
] && ipold="$(< "$ipfile" )"
ipnew="$( wget -q -O - checkip.dyndns.org | sed -e 's/.*Current IP Address: //;s/<.*$//' )"
#... (6 Replies)
o/p of my command is given below
My requirement is
if Pnumber is 0 then
stabilization.Build.2013
else
stabilization.PBuild.2013.3 (11 Replies)
Discussion started by: nikhil jain
11 Replies
LEARN ABOUT SUNOS
test
test(1F) FMLI Commands test(1F)NAME
test - condition evaluation command
SYNOPSIS
test expression
expression
DESCRIPTION
test evaluates the expression expression and if its value is true, sets a 0 (TRUE) exit status; otherwise, a non-zero (FALSE) exit status
is set; test also sets a non-zero exit status if there are no arguments. When permissions are tested, the effective user ID of the process
is used.
All operators, flags, and brackets (brackets used as shown in the second SYNOPSIS line) must be separate arguments to test. Normally these
items are separated by spaces.
USAGE
Primitives
The following primitives are used to construct expression:
-r filename True if filename exists and is readable.
-w filename True if filename exists and is writable.
-x filename True if filename exists and is executable.
-f filename True if filename exists and is a regular file.
-d filename True if filename exists and is a directory.
-c filename True if filename exists and is a character special file.
-b filename True if filename exists and is a block special file.
-p filename True if filename exists and is a named pipe (FIFO).
-u filename True if filename exists and its set-user-ID bit is set.
-g filename True if filename exists and its set-group-ID bit is set.
-k filename True if filename exists and its sticky bit is set.
-s filename True if filename exists and has a size greater than 0.
-t[fildes] True if the open file whose file descriptor number is fildes (1 by default) is associated with a terminal
device.
-z s1 True if the length of string s1 is 0.
-n s1 True if the length of the string s1 is non-zero.
s1 = s2 True if strings s1 and s2 are identical.
s1 != s2 True if strings s1 and s2 are not identical.
s1 True if s1 is not the null string.
n1 -eq n2 True if the integers n1 and n2 are algebraically equal. Any of the comparisons -ne, -gt, -ge, -lt, and -le
may be used in place of -eq.
Operators
These primaries may be combined with the following operators:
! Unary negation operator.
-a Binary and operator.
-o Binary or operator (-a has higher precedence than -o).
`(expression)` Parentheses for grouping. Notice also that parentheses are meaningful to the shell and, therefore,
must be quoted.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO find(1), sh(1), attributes(5)NOTES
If you test a file you own (the -r , -w , or -x tests), but the permission tested does not have the owner bit set, a non-zero (false) exit
status will be returned even though the file may have the group or other bit set for that permission. The correct exit status will be set
if you are super-user.
The = and != operators have a higher precedence than the -r through -n operators, and = and != always expect arguments; therefore, = and !=
cannot be used with the -r through -n operators.
If more than one argument follows the -r through -n operators, only the first argument is examined; the others are ignored, unless a -a or
a -o is the second argument.
SunOS 5.10 5 Jul 1990 test(1F)