Sponsored Content
Top Forums UNIX for Beginners Questions & Answers Seeking clarification: function within if conditional Post 302992305 by drysdalk on Thursday 23rd of February 2017 03:37:06 PM
Old 02-23-2017
Hi,

Firstly, it might be helpful to discuss the distinction between a command and a function. The Bash built-in evaluator 'if' is capable of evaluating both of these things. So it can test the result of either an external command (like 'nslookup' in your examples here), or the result of a function contained in a script. If it's testing an external command it will look at the exit value, and if it's an internal function it will be the return value of the fuction.

So in your case, when the external command 'nslookup' has an exit status of 0 the 'if' check passes as true, and when it has an exit status of 1 it checks as false. In turn, 'nslookup' itself will exit with 0 if it could resolve the hostname and nothing else went wrong, and with a non-zero value if it couldn't resolve the hostname or if it encountered some other problem along the way that stopped it from doing so.

Hope this helps.
This User Gave Thanks to drysdalk For This Post:
 

8 More Discussions You Might Find Interesting

1. Filesystems, Disks and Memory

seeking a doc on lvm etc...

Hi. I wanted to increase my knowledge base with unix. can you help me find a like that talks about luns, physical volumes, volume groups, logical volumes then mountpoints? i would appreciate it thanks Jigar (1 Reply)
Discussion started by: jigarlakhani
1 Replies

2. UNIX for Dummies Questions & Answers

Seeking help...Urgent!!! Please help me...

Can any1 please help me answer a couple of this question? 1) What is the process management of UNIX? (single task, multitasks, etc...) 2) What is the process management of Linux? (single task, multitasks, etc...) 3) What is the type of process of UNIX? (process, thread, etc...) 4)... (1 Reply)
Discussion started by: blind02002
1 Replies

3. Shell Programming and Scripting

seeking help with shell script

I am trying to update a script which I had created to monitor tablespace usage. Originally the sql spooled out to a text file anything with more than 75% used. I have been asked to change this. Now the sql must spool out all tablespaces. The script I have to write should scan the file for... (4 Replies)
Discussion started by: Niadh
4 Replies

4. Programming

Seeking Some libs for AIX 5.3

hello everybody! I m compiling some program with the g++ on AIX 5.3 and it needs some library that i didn't find them i am new with the AIX here is the compilation error : g++ -Daix -fpic -o printps -lxercesc1_1 -L/oracle/OraHome/lib32/ -L/epost2/blitz/lib -lhmltods -lhmltops -lgeneric... (0 Replies)
Discussion started by: eternalflame
0 Replies

5. Shell Programming and Scripting

seeking help in text processing

Hi, I am a newbie in shell scripting. I want to get an expert help in solving a text processing issue. The issue I am facing is that, in the below log file contents I need to extract each block of lines (it could be a single line also) based on some regular expression and store it in... (8 Replies)
Discussion started by: Alecs
8 Replies

6. Shell Programming and Scripting

[grep] seeking more than one word

Hello everybody, How can I do seek several words with grep command ? I didn't find how to do that in the man for I'm French. Then I tried man bash | grep -in control flow But flow is interpreted as an input file Then I tried man bash | grep -in "control" -a "flow" but doesn't seem to work... (4 Replies)
Discussion started by: Oddant
4 Replies

7. Shell Programming and Scripting

Seeking help with search

Hello All, I'm looking for some help with grepping for two specific strings in files with multiple lines. For instance, I have files and the content looks like this: =====Start===== Record:1 Field 1 = aaaaaaaaaa Field 2 = bbbbbbbbbb Field 3 = 1234567890 ... (9 Replies)
Discussion started by: bbbngowc
9 Replies

8. Shell Programming and Scripting

Seeking Alternative for diff in hp

Hi , I have to use HP-unix OS to get difference between 2 files.while i tried a piece of code in other OS(linux/unix) as below, it worked fine & the output is desired one. diff --suppress-common-lines -y file_1 file_2 >d.txt The same doesn't works in HP -unix. Any help shall be... (6 Replies)
Discussion started by: vinil
6 Replies
XmScrollVisible(3X)													       XmScrollVisible(3X)

NAME
XmScrollVisible - A ScrolledWindow function that makes an invisible descendant of a ScrolledWindow work area visible SYNOPSIS
#include <Xm/ScrolledW.h> void XmScrollVisible (scrollw_widget, widget, left_right_margin, top_bottom_margin) Widget scrollw_widget; Widget widget; Dimension left_right_margin; Dimension top_bottom_margin; DESCRIPTION
XmScrollVisible makes an obscured or partially obscured widget or gadget descendant of a ScrolledWindow work area visible. The function repositions the work area and sets the specified margins between the widget and the nearest viewport boundary. The widget's location rela- tive to the viewport determines whether one or both of the margins must be adjusted. This function requires that the XmNscrollingPolicy of the ScrolledWindow widget be set to XmAUTOMATIC. Specifies the ID of the ScrolledWindow widget whose work area window contains an obscured descendant. Specifies the ID of the widget to be made visible. Specifies the margin to establish between the left or right edge of the widget and the associated edge of the viewport. This margin is established only if the widget must be moved horizontally to make it visi- ble. Specifies the margin to establish between the top or bottom edge of the widget and the associated edge of the viewport. This margin is established only if the widget must be moved vertically to make it visible. For a complete definition of ScrolledWindow and its associated resources, see XmScrolledWindow(3X). SEE ALSO
XmScrolledWindow(3X) XmScrollVisible(3X)
All times are GMT -4. The time now is 02:56 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy