Sponsored Content
Top Forums Shell Programming and Scripting Multiple co-processor file descriptors Post 64819 by tmarikle on Wednesday 2nd of March 2005 01:38:16 PM
Old 03-02-2005
Sorry, again, I am not trying to bump anything up, I have a core issue, that I am trying to narrow this thread's scope to focus on, using "eval" that is eluding me so if I can get past this, my problem is solved.

Essentially my "x" variable should be able to translate into another variable containing my file descriptor. If I can get "x" to expand into TEXTVAR2_stdout and then expand this so that "4" can be assigned to a local function variable, I am golden.

Code:
#!/usr/bin/ksh

sqlplus -s /nolog |&

x=TESTVAR2

eval export "${x}_stdout=3"
eval export "${x}_stdin=4"

# Print using named variables
print $TESTVAR2_stdout
print $TESTVAR2_stdin

# Same thing attempting expansion of my "x" variable;
# results in print TESTVAR2_stdout but no 4
eval "print ${x}_stdout"
# results in print $TESTVAR2_stdout
print $(expr $"${x}_stdout")

I get down to something that looks like $TESTVAR2_stdout but I cannot get the shell to treat it as a variable.

Thomas
 

10 More Discussions You Might Find Interesting

1. Programming

File Descriptors

Hi, I have written a daemon process, to perform certain operations in the background. For this I have to close, the open file descriptors, Does anybody know how to find out the number of open file descriptors ? Thanks in Advance, Sheetal (2 Replies)
Discussion started by: s_chordia
2 Replies

2. UNIX for Advanced & Expert Users

File Descriptors

Hello all, A few questions on file descriptors ... scenario : Sun Ultra 30 with Sun OS 5.5.1 , E250 with Solaris 2.6 In one of my servers, the file descriptor status from the soft limit and hard limits are 64 and 1024 respectively for root user. Is the soft limit (64) represents the... (3 Replies)
Discussion started by: shibz
3 Replies

3. UNIX for Dummies Questions & Answers

file descriptors

i m trying to learn processes in unix and i've been reading this but i don't quite get it. its regarding file descriptors. : each is a part of file pointers, they point to another area. indexes into an Operating system maintained table called "file descriptor table". one table per process. may... (3 Replies)
Discussion started by: a25khan
3 Replies

4. Programming

Sockets and File descriptors

I am in a Systems programming class this semester, and our current project is to write a program utilizing sockets and fork. For the project, I decided to make my own instant messaging program. I have the code completed, but I have a problem that keeps old clients from communicating with new... (3 Replies)
Discussion started by: gstlouis
3 Replies

5. UNIX for Advanced & Expert Users

File descriptors missing on startup

Dec 20 15:34:32 hostname sendmail: File descriptors missing on startup: stderr; Bad file number Dec 20 15:34:32 hostname sendmail: File descriptors missing on startup: stderr; Bad file number Dec 20 15:34:32 hostname sendmail: File descriptors missing on startup: stderr; Bad file number Dec... (1 Reply)
Discussion started by: xnightcrawl
1 Replies

6. UNIX for Advanced & Expert Users

File Descriptors + cron

Hi All, This thread is going to be a discussion basically bringing out more information from the experts on cron jobs and the associated file handles. So, here is the question. There is definitely a constant ' n ' as the maximum number of file handles alloted to a process ' p '. Will... (7 Replies)
Discussion started by: matrixmadhan
7 Replies

7. UNIX for Dummies Questions & Answers

Write/read to file descriptors

Is it possible to write to file descriptor 0 and read from 1 or 2? How could this be implemented? (3 Replies)
Discussion started by: machshev
3 Replies

8. HP-UX

exec and file descriptors

Hi, I speak and write english more or less, so I hope my asking be clear. :) In the company I am working, they are using control-m software to lunch shell scripts. So i put this command in all shell scripts: export LOGFILE_tmp=$PRODUC_DATA/tmp/${SCRIPT}_${PAIS}_`date... (0 Replies)
Discussion started by: anamcara
0 Replies

9. UNIX for Dummies Questions & Answers

Semaphores and File Descriptors

What is the difference between a file descriptor and a semaphore? My basic understanding is: - a file descriptor is a small positive integer that the system uses instead of the file name to identify an open file or socket. - a semaphore is a variable with a value that indicates the... (1 Reply)
Discussion started by: Mr_Webster
1 Replies

10. Shell Programming and Scripting

Questions about file descriptors

Hi, I'm playing with KSH I entered following command in terminal { echo "stdout" >&1; echo "stderr" >&2; } > out And I get only stoud in a new file out. My question is: Where did my stderr vanish ? (5 Replies)
Discussion started by: solaris_user
5 Replies
variable(n)						       Tcl Built-In Commands						       variable(n)

__________________________________________________________________________________________________________________________________________________

NAME
variable - create and initialize a namespace variable SYNOPSIS
variable ?name value...? name ?value? _________________________________________________________________ DESCRIPTION
This command is normally used within a namespace eval command to create one or more variables within a namespace. Each variable name is initialized with value. The value for the last variable is optional. If a variable name does not exist, it is created. In this case, if value is specified, it is assigned to the newly created variable. If no value is specified, the new variable is left undefined. If the variable already exists, it is set to value if value is specified or left unchanged if no value is given. Normally, name is unqualified (does not include the names of any containing namespaces), and the variable is created in the current namespace. If name includes any namespace qualifiers, the variable is created in the specified names- pace. If the variable is not defined, it will be visible to the namespace which command, but not to the info exists command. If the variable command is executed inside a Tcl procedure, it creates local variables linked to the corresponding namespace variables (and therefore these variables are listed by info vars.) In this way the variable command resembles the global command, although the global command only links to variables in the global namespace. If any values are given, they are used to modify the values of the associated namespace variables. If a namespace variable does not exist, it is created and optionally initialized. A name argument cannot reference an element within an array. Instead, name should reference the entire array, and the initialization value should be left off. After the variable has been declared, elements within the array can be set using ordinary set or array commands. EXAMPLES
Create a variable in a namespace: namespace eval foo { variable bar 12345 } Create an array in a namespace: namespace eval someNS { variable someAry array set someAry { someName someValue otherName otherValue } } Access variables in namespaces from a procedure: namespace eval foo { proc spong {} { # Variable in this namespace variable bar puts "bar is $bar" # Variable in another namespace variable ::someNS::someAry parray someAry } } SEE ALSO
global(n), namespace(n), upvar(n) KEYWORDS
global, namespace, procedure, variable Tcl 8.0 variable(n)
All times are GMT -4. The time now is 10:25 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy