Sponsored Content
Top Forums Shell Programming and Scripting Interpreting Logicals/Environment Variables using the read command Post 302320196 by kingpin2502 on Wednesday 27th of May 2009 09:58:35 AM
Old 05-27-2009
Interpreting Logicals/Environment Variables using the read command

Hi All

I have something that from the outset seems really trivial but in practice is not quite working.

I have the following code sample in my shell script which illustrates the problem

Code:
echo "enter home directory"
read home
mkdir $home/newdir

The user then enters a logical $HOME in the prompt. This is what is displayed on the screen

Code:
enter home directory
$HOME
mkdir: cannot create directory `$HOME/newdir': No such file or directory

If I type the full name into the prompt, it works fine. But this isn't ideal as in the real script, the directory structure could be 10 directories deep. Typing the full path could lead to potential issues.

Is there some way for the read command to interpret environment variables?

Thanks
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

help..Environment variables...

hi, 1). i would like to know what is meant by environment variables? 2). is the number of envi variables is a constant number for unix systems? 3). how to see the list of envi variables (and the values of the envi variables)in a single command? 4). if this questions were already asked... (3 Replies)
Discussion started by: sekar sundaram
3 Replies

2. Programming

environment variables

hi, I want to create a new EV(Environment Variable) through a c program and I done this thing through setenv() method. But the newly created EV is not permanent, i.e. when I exit from the program the EV also no longer lives. But I want to make it a permanent EV for the current user. Actually I... (6 Replies)
Discussion started by: sumsin
6 Replies

3. UNIX for Dummies Questions & Answers

trouble using read to store values in variables from command output

I know there are caveats about using read in pipelines because read is treated by a subshell. I know this but I can't think of any way to accomplish this regardless, I'm still a rookie. I hope somebody will be able to interpret what it is that I'm trying to accomplish and correct me. ... (2 Replies)
Discussion started by: ProGrammar
2 Replies

4. Shell Programming and Scripting

using environment variables

say i define an environment variable in a particular script (upgrade.sh). my script is upgarde.sh and it calls another script try.sh. will this environment variable be accessible to try.sh also. if not how to I make environment variables global so that they can be used by any script. (2 Replies)
Discussion started by: lassimanji
2 Replies

5. Shell Programming and Scripting

how to write 2 variables while using read command

Hello All i have input files contains 2 values as following 20-Oct-09 Z59408009 20-Oct-09 Z59423060 and i am using the following script cat /home/or/input.txt | awk '{print $2}' >log count=0 while read line; do count=$(( count + 1 )) echo "UPDATE SAT_JRLTRT SET AVT='X' WHERE... (6 Replies)
Discussion started by: mogabr
6 Replies

6. Shell Programming and Scripting

Environment Variables in text file and read command

I cannot get the following substitution ($ORACLE_SID) to work: The variable ORACLE_SID is set to wardin my environment. It has been exported. I have a text file called test.dat: /u07/oradata/${ORACLE_SID}/extab/finmart/summit/ps_voucher_line_crnt_ex.dbf... (2 Replies)
Discussion started by: bradyd
2 Replies

7. HP-UX

Environment Variables

Hi Experts, Need your help in understanding the commands to setup the environment variables in hp-ux. Beleive need to use either set,setenv or export. I am confused between above three options, when to use which option? On command line, I have tried both set and setenv but couldn't... (1 Reply)
Discussion started by: sai_2507
1 Replies

8. HP-UX

Environment Variables

Hi All, I need to understand following three environment variables and their usages in HP Unix. _M_ARENA_OPTS _M_CACHE_OPTS PTHREAD_SCOPE_SYSTEM How does these environment variables influence multi threaded applciation and how do we decide the value of these variables? Is there... (0 Replies)
Discussion started by: angshuman
0 Replies

9. UNIX for Beginners Questions & Answers

Interpreting Linux's free command output

I have two questions on Linux's free command. Below, I have provided output from my home laptop (fedora 26 ) which has 16GB Physical RAM and a production server (RHEL 7.4) which has 24GB RAM. Question1. What exactly does the buffer/cache column say in free command's output ? buffer/cache is... (9 Replies)
Discussion started by: omega3
9 Replies

10. Shell Programming and Scripting

Read several variables from command output via SSH

Hi Folks, I'm currently trying to read several values into different variables. Actually, what I'm doing works, but I get an error message. My attempts are: read strCPROC strIPROC strAPROC <<<$(ssh -n -T hscroot@$HMC "lshwres -r proc -m $strIDENT --level sys -F \"configurable_sys_proc_units... (11 Replies)
Discussion started by: NKaede
11 Replies
NPM-RUN-SCRIPT(1)                                                                                                                NPM-RUN-SCRIPT(1)

NAME
npm-run-script - Run arbitrary package scripts SYNOPSIS
npm run-script <command> [--silent] [-- <args>...] alias: npm run DESCRIPTION
This runs an arbitrary command from a package's "scripts" object. If no "command" is provided, it will list the available scripts. run[-script] is used by the test, start, restart, and stop commands, but can be called directly, as well. When the scripts in the package are printed out, they're separated into lifecycle (test, start, restart) and directly-run scripts. As of ` https://blog.npmjs.org/post/98131109725/npm-2-0-0, you can use custom arguments when executing scripts. The special option -- is used by getopt https://goo.gl/KxMmtG to delimit the end of the options. npm will pass all the arguments after the -- directly to your script: npm run test -- --grep="pattern" The arguments will only be passed to the script specified after npm run and not to any pre or post script. The env script is a special built-in command that can be used to list environment variables that will be available to the script at run- time. If an "env" command is defined in your package, it will take precedence over the built-in. In addition to the shell's pre-existing PATH, npm run adds node_modules/.bin to the PATH provided to scripts. Any binaries provided by locally-installed dependencies can be used without the node_modules/.bin prefix. For example, if there is a devDependency on tap in your package, you should write: "scripts": {"test": "tap test/*.js"} instead of "scripts": {"test": "node_modules/.bin/tap test/*.js"} to run your tests. The actual shell your script is run within is platform dependent. By default, on Unix-like systems it is the /bin/sh command, on Windows it is the cmd.exe. The actual shell referred to by /bin/sh also depends on the system. As of ` https://github.com/npm/npm/releases/tag/v5.1.0 you can customize the shell with the script-shell configuration. Scripts are run from the root of the module, regardless of what your current working directory is when you call npm run. If you want your script to use different behavior based on what subdirectory you're in, you can use the INIT_CWD environment variable, which holds the full path you were in when you ran npm run. npm run sets the NODE environment variable to the node executable with which npm is executed. Also, if the --scripts-prepend-node-path is passed, the directory within which node resides is added to the PATH. If --scripts-prepend-node-path=auto is passed (which has been the default in npm v3), this is only performed when that node executable is not found in the PATH. If you try to run a script without having a node_modules directory and it fails, you will be given a warning to run npm install, just in case you've forgotten. You can use the --silent flag to prevent showing npm ERR! output on error. You can use the --if-present flag to avoid exiting with a non-zero exit code when the script is undefined. This lets you run potentially undefined scripts without breaking the execution chain. SEE ALSO
o npm help 7 scripts o npm help test o npm help start o npm help restart o npm help stop o npm help 7 config January 2019 NPM-RUN-SCRIPT(1)
All times are GMT -4. The time now is 09:05 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy