Sponsored Content
Top Forums Shell Programming and Scripting Bash Positional Parameters Question Post 302617517 by jim mcnamara on Monday 2nd of April 2012 09:36:17 PM
Old 04-02-2012
This is from tldp.org - based on your question history I would strongly advise you to read:

Advanced Bash-Scripting Guide

You can download a pdf from there. It is all free.

This is from the getopts page. Among lots of other things it explains getopts use of the : character

Code:
while getopts ":abcde:fg" Option
# Initial declaration.
# a, b, c, d, e, f, and g are the options (flags) expected.
# The : after option 'e' shows it will have an argument passed with it.
do
case $Option in
a ) # Do something with variable 'a'.
b ) # Do something with variable 'b'.
...
e) # Do something with 'e', and also with $OPTARG,
# which is the associated argument passed with option 'e'.
...
g ) # Do something with variable 'g'.
esac
done

$OPTARG would be the value of -t filename where "t:" exists in the the format string.
There is also an example of how to handle trailing arguments that are not options.
This User Gave Thanks to jim mcnamara For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Positional Parameters

HPUX11.0/Korn Shell I have an old script that takes in a series of arguments when its called. The script is really more of a common set of functions that gets called by other scripts as needed. I have been asked to make this into a menu driven script to rollout to app support for their use during... (2 Replies)
Discussion started by: google
2 Replies

2. UNIX for Dummies Questions & Answers

Positional Parameters

Hello, I am using the Bourne shell. I am trying to understand the concept of positional parameters. I do understand that positional parameters: 1. Are initialized by shell 2. Have a max of 9 parameters ($1 to $9) 3. Have no limit on the number of arguments 4. Can be rearranged... (15 Replies)
Discussion started by: ericelysia
15 Replies

3. UNIX for Dummies Questions & Answers

Positional parameters

I need to get file names from commandline arguments, it may be any no of arguements, Using for loop i got but how do i display it, bcoz $i will give the number i is assigned $$i is not working either $($i), i need the names of the files got in the arguement (2 Replies)
Discussion started by: shalu@ibm
2 Replies

4. Shell Programming and Scripting

Setting "default" positional parameters (in bash)

Hi, I have a script that processes the positional parameters provided on the command line, or - if none are provided - uses some defaults instead. I've currently got it written as follows, which works like a charm, but I was wondering if there is a different/other/better/... way of doing... (2 Replies)
Discussion started by: pvdb
2 Replies

5. UNIX for Dummies Questions & Answers

Positional Parameters

Can someone tell me in more layman's terms what positional parameters are and give a good example? My book again is confusing me. :confused: (1 Reply)
Discussion started by: Straitsfan
1 Replies

6. Shell Programming and Scripting

checking the positional parameters

Hi all, I have one small requirment... I have prepared one script. we have to pass two possitional parameters to the script. What I want to do is if the parameters are not passed then i dont want the script to start the process... For ex: $ ./a.sh parm1 parm2 #Here, it can start... (7 Replies)
Discussion started by: raghu.iv85
7 Replies

7. Shell Programming and Scripting

How to call a bash script with positional parameters?

Hi, I have a script which will be executed using the below command, bin/nutch crawl urls -dir /data/test/ bin/nutch - Script file crawl, urls, /data/test/ - Parameters -dir - Option The above script should executed from a shell script named test.sh. I have the below code to execute... (2 Replies)
Discussion started by: vel4ever
2 Replies

8. UNIX for Dummies Questions & Answers

Default values for positional parameters - dummy question I think

Hi, Sorry for a dummy question I believe. I am just wanting to know how do I assign a default $1 argument if one is not provided. At the moment, I am doing something like below: arg1="${1:-foo}"And then I check $arg1 in case/esac. I am just wondering if there is a way for me to simply do... (3 Replies)
Discussion started by: newbie_01
3 Replies

9. UNIX for Beginners Questions & Answers

'sed' with Positional Parameters

I'm new with 'sed' and for sure something still I don't understand yet with it. If you see my output on ">Output..." portion, the new directory still on "source_dir" instead of "dest_dir". You may disregard for the "tar" part, this is just a test script, just for me to understand 'sed' using the... (3 Replies)
Discussion started by: daryl0505
3 Replies

10. UNIX for Beginners Questions & Answers

Positional parameters in if statement

I am trying to code an if statement that accepts two parameters and see if those parameters are in another file called teledir.txt. If it already exists in the file, it is to say "Entry Exists". If not, I add it to the file and say "Entry Added". This is the code I have so far: if ; then ... (1 Reply)
Discussion started by: Eric7giants
1 Replies
getoptcvt(1)                                                       User Commands                                                      getoptcvt(1)

NAME
getoptcvt - convert to getopts to parse command options SYNOPSIS
/usr/lib/getoptcvt [-b] filename /usr/lib/getoptcvt DESCRIPTION
/usr/lib/getoptcvt reads the shell script in filename, converts it to use getopts instead of getopt, and writes the results on the standard output. getopts is a built-in Bourne shell command used to parse positional parameters and to check for valid options. See sh(1). It supports all applicable rules of the command syntax standard (see Rules 3-10, intro(1)). It should be used in place of the getopt command. (See the NOTES section below.) The syntax for the shell's built-in getopts command is: getopts optstring name [ argument...] optstring must contain the option letters the command using getopts will recognize; if a letter is followed by a colon (:), the option is expected to have an argument, or group of arguments, which must be separated from it by white space. Each time it is invoked, getopts places the next option in the shell variable name and the index of the next argument to be processed in the shell variable OPTIND. Whenever the shell or a shell script is invoked, OPTIND is initialized to 1. When an option requires an option-argument, getopts places it in the shell variable OPTARG. If an illegal option is encountered, ? will be placed in name. When the end of options is encountered, getopts exits with a non-zero exit status. The special option -- may be used to delimit the end of the options. By default, getopts parses the positional parameters. If extra arguments (argument ...) are given on the getopts command line, getopts parses them instead. So that all new commands will adhere to the command syntax standard described in intro(1), they should use getopts or getopt to parse posi- tional parameters and check for options that are valid for that command (see the NOTES section below). OPTIONS
The following option is supported: -b Makes the converted script portable to earlier releases of the UNIX system. /usr/lib/getoptcvt modifies the shell script in file- name so that when the resulting shell script is executed, it determines at run time whether to invoke getopts or getopt. EXAMPLES
Example 1: Processing the arguments for a command The following fragment of a shell program shows how one might process the arguments for a command that can take the options -a or -b, as well as the option -o, which requires an option-argument: while getopts abo: c do case $c in a | b) FLAG=$c;; o) OARG=$OPTARG;; ?) echo $USAGE exit 2;; esac done shift `expr $OPTIND - 1` Example 2: Equivalent code expressions This code accepts any of the following as equivalent: cmd -a -b -o "xxx z yy" filename cmd -a -b -o "xxx z yy" -filename cmd -ab -o xxx,z,yy filename cmd -ab -o "xxx z yy" filename cmd -o xxx,z,yy b a filename ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of getopts: LC_CTYPE, LC_MESSAGES, and NLSPATH. OPTIND This variable is used by getoptcvt as the index of the next argument to be processed. OPTARG This variable is used by getoptcvt to store the argument if an option is using arguments. EXIT STATUS
The following exit values are returned: 0 An option, specified or unspecified by optstring, was found. >0 The end of options was encountered or an error occurred. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ SEE ALSO
intro(1), getopts(1), sh(1), shell_builtins(1), getopt(3C), attributes(5) DIAGNOSTICS
getopts prints an error message on the standard error when it encounters an option letter not included in optstring. NOTES
Although the following command syntax rule (see intro(1)) relaxations are permitted under the current implementation, they should not be used because they may not be supported in future releases of the system. As in the EXAMPLES section above, -a and -b are options, and the option -o requires an option-argument. The following example violates Rule 5: options with option-arguments must not be grouped with other options: example% cmd -aboxxx filename The following example violates Rule 6: there must be white space after an option that takes an option-argument: example% cmd -ab oxxx filename Changing the value of the shell variable OPTIND or parsing different sets of arguments may lead to unexpected results. SunOS 5.10 7 Jan 2000 getoptcvt(1)
All times are GMT -4. The time now is 01:57 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy