Extracting unknown positional parameter in Bourne shell
I have a variable that contains the number of a positional parameter. There is no way of knowing what number this may be, although it is guaranteed to correspond with a valid parameter.
In BASH I could just use ${@[$var]} to extract that argument. But in a Bourne shell the best I can come up with is to use a for-loop with a counter as in this sample script (where the first parameter is the position to extract from those that follow):
Hi .
I am new to Unix. So i have a tough time.
we are using Korn Shell. I have a scenario where i have three files namely
xxx01,xxx02,xxx03. Now when i write ls xxx*|wc -l output is 3. But then i write `ls $1|wc -l` and pass xxx* as positional parameter (sh yyy.sh xxx*)
output is xxx01. other... (1 Reply)
Hi .
I am new to Unix. So i have a tough time.
we are using Korn Shell. I have a scenario where i have three files namely
xxx01,xxx02,xxx03. Now when i write ls xxx*|wc -l output is 3. But then i write `ls $1|wc -l` and pass xxx* as positional parameter (sh yyy.sh xxx*)
output is xxx01. other... (1 Reply)
I do not claim to be an expert, but I have done things with scripts that whole teams of folks have said can not be done. Of course they should have said we do not have the intestinal fortitude to git-r-done.
I have been using UNIX actually HPUX since 1992. Unfortunately my old computer died and... (7 Replies)
Hi All,
When passing parameters to a sheel script, the parameters are referenced by their positions such as $1 for first parameter, $2 for second parameter. these positional values can only have values ranging from $0-$9 (0,1,2,3...9).
I have a shell script meant to accept 20 parameters. for... (3 Replies)
Hello All,
I am trying to clean up a poorly looking awk command. I am searching for a way to define a range of positional parameters. I may not be searching for the correct syntax.
Example:
awk ' /14:3*/ {print $2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13}' app.log
Is it possible to shorten... (4 Replies)
Hi All
I have writing a Korn Shell script to execute it on many of our servers. But some servers don't have Korn Shell installed, they use Borne Shell.
Some operations like calculation don't work :
cat ${file1} | tail -$((${num1}-${num2})) > ${file2}
Is it possible to activate Korn Shell... (3 Replies)
Could some one tell me the difference btw Bourne shell and the Kshell? Which is more flexible and reliable in terms of portability and efficiency. When i type the following command ..
$ echo $SHELL
yields me
/bin/sh
Does this tells me that I am in Bourne shell. If yes, how can i get... (6 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
STEP 1: Create a Bash shell script (myscript) inside the a2 directory. The script should allow the user to pass... (3 Replies)
A severe vulnerability was discovered in Bourne shell.
Just google for: bash vulnerability
... for more details. (5 Replies)
Discussion started by: Cochise
5 Replies
LEARN ABOUT OPENSOLARIS
shift
shift(1) User Commands shift(1)NAME
shift - shell built-in function to traverse either a shell's argument list or a list of field-separated words
SYNOPSIS
sh
shift [n]
csh
shift [variable]
ksh
*shift [n]
ksh
+shift [n]
DESCRIPTION
sh
The positional parameters from $n+1 ... are renamed $1 ... . If n is not specified, it is assumed to be 1.
csh
The components of argv, or variable, if supplied, are shifted to the left, discarding the first component. It is an error for the variable
not to be set or to have a null value.
ksh
The positional parameters from $n+1 $n+1 ... are renamed $1 ..., default n is 1. The parameter n can be any arithmetic expression that
evaluates to a non-negative number less than or equal to $#.
On this manual page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a
variable assignment. This means that tilde substitution is performed after the = sign and word splitting and file name genera-
tion are not performed.
ksh93
shift is a shell special built-in that shifts the positional parameters to the left by the number of places defined by n, or 1 if n is
omitted. The number of positional parameters remaining is reduced by the number of places that are shifted.
If n is specified, it is evaluated as an arithmetic expression to determine the number of places to shift. It is an error to shift more
than the number of positional parameters or a negative number of places.
The following exit values are returned by shift in ksh93:
0 Successful completion. The positional parameters were successfully shifted.
>0 An error occurred.
On this manual page, ksh93(1) commands that are preceded by one or two + are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. They are not valid function names.
5. Words, following a command preceded by ++ that are in the format of a variable assignment, are expanded with the same rules as a
variable assignment. This means that tilde substitution is performed after the = sign and field splitting and file name genera-
tion are not performed.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), ksh(1), ksh93(1), sh(1), attributes(5)SunOS 5.11 20 Nov 2007 shift(1)