Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Exec explanation needed
Top Forums UNIX for Dummies Questions & Answers Exec explanation needed Post 302182099 by era on Saturday 5th of April 2008 11:16:12 AM
Old 04-05-2008
It opens file descriptor 3 to read from the file. This seems rather superfluous, as the same can be done by reading straight from the file. The final exec closes the file descriptor again after the loop is finished.

You seem to be missing the variable name on the "read".

Code:
while read REPLY
do
  echo "The number is $REPLY"
  a.out "$REPLY"
done <data

File descriptors are useful as such, and if this was originally part of a bigger program where different files were accessed at different times, it might have made sense originally.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

sed command explanation needed

Hi, Could you please explain me the below statement -- phrase wise. sed -e :a -e '$q;N;'$cnt',$D;ba' abc.txt > xyz.txt if suppose $cnt contains value: 10 it copies last 9 lines of abc.txt to xyz.txt why it is copying last 9 rather than 10. and also what is ba and $D over there in... (4 Replies)
Discussion started by: subbukns
4 Replies

2. UNIX for Dummies Questions & Answers

In need of explanation

Its great someone provided this script that strips out a filename and extension but can someone explain how each line works? file1='Jane Mid Doe.txt' newfile='Jane.txt' 1) ext=${file1##*.} 2) filename=${file%%.???} 3) set -- $filename 4) newfile="1.$extension" (1 Reply)
Discussion started by: Lillyt
1 Replies

3. Solaris

showrev output explanation needed

hi this is the output of showrev command from my sun blade 150 machine. bash-3.00# showrev Hostname: u15_9 Hostid: 83685284 Release: 5.10 Kernel architecture: sun4u Application architecture: sparc Hardware provider: Sun_Microsystems Domain: sun.com Kernel version: SunOS 5.10... (1 Reply)
Discussion started by: kingston
1 Replies

4. Shell Programming and Scripting

Explanation Needed

Hi all, I'm very new to UNIX. I have got a coding, where i dont understand the below part. Could someone please explain it in detail? awk 'NR > 1; NR == 1 { S = $0 } END { print S }' $textfile.bak > $textfile could someone explain what awk 'NR > 1; NR == 1 { S = $0 } END { print S }' ... (1 Reply)
Discussion started by: raghulshekar
1 Replies

5. Programming

Python 3.1 TypeError explanation needed

Could someone explain why Python 3.1 errors out below? Do I need an additional module that's not required in 3.2 perhaps? I need to use 3.1 as it's the version available on a server I am using. Python 3.2.1rc1 (default, May 18 2011, 11:01:17) on linux2 Type "help", "copyright", "credits"... (0 Replies)
Discussion started by: jelloir
0 Replies

6. Shell Programming and Scripting

Script Variables Inquiry, Values Okay in Standalone Exec, No-Show in Cron Exec

I have the following bash script lines in a file named test.sh. #!/bin/bash # # Write Date to cron.log # echo "Begin SSI Load $(date +%d%b%y_%T)" # # Get the latest rates file for processing. # d=$(ls -tr /rms/data/ssi | grep -v "processed" | tail -n 1) filename=$d export filename... (3 Replies)
Discussion started by: ginowms
3 Replies

7. UNIX for Advanced & Expert Users

Grep - Explanation needed.

grep -E '^(++){5}5000' <file_name> this command searches value 5000 in only 6th column from provided file where pipe ( | )is delimiter which separate columns... can some one plz explain me what '^(++){5}5000' actually does..? :confused: (1 Reply)
Discussion started by: Killer420
1 Replies

8. Shell Programming and Scripting

Little explanation needed on array

I had gone through..google search.....and unix user post.......where I found so many ways of accessing files..... suppose if I am having 4 files, each file is having 3 columns, and I want to use each field of each column, then how can I use it.. how can I create array for each file's each column,... (8 Replies)
Discussion started by: Dona Clara
8 Replies

9. Shell Programming and Scripting

Value Too Great for Base Error, Explanation and Workout needed

Hey Friends, its me again! :o I was asked to create a script that would go into our backup directories and delete/purge anything in the directory after a certain amount of days, normally I would be able to write something up that goes to the directory finds it and deletes it. cd... (12 Replies)
Discussion started by: gkelly1117
12 Replies

10. UNIX for Beginners Questions & Answers

Explanation for Scripts Inner Workings Needed

#!/bin/bash n=$l; typeset -a v x=$(< input.dat) check(){ if; then sed 's/Test/Proc/g' file.sh >fl.sh else exit 13 fi } check $n while ; do x=`expr $x -l` v=$x done less fi.sh l>/dev/null&& echo yes || exit 1 echo v= ${v } exit 0 I have file.sh and input.dat in the current... (3 Replies)
Discussion started by: bananasprite
3 Replies

LEARN ABOUT HPUX

fmt

fmt(1)							      General Commands Manual							    fmt(1)

NAME

       fmt - format text

SYNOPSIS

       width] [file...]

DESCRIPTION

       The  command is a simple text formatter that fills and joins lines to produce output lines of (up to) the number of characters specified in
       the width option.  The default width is 72.  concatenates the arguments.  If none are given, formats text from the standard input.

       Blank lines are preserved in the output, as is the spacing between words.  does not fill lines beginning with a	period	for  compatibility
       with Nor does it fill lines starting with

       Indentation is preserved in the output and input lines with differing indentation are not joined (unless is used).

       can also be used as an in-line text filter for the command:

       reformats the text between the cursor location and the end of the paragraph.

   Options
       recognizes the following options:

	      Crown margin mode.
		    Preserve the indentation of the first two lines within a paragraph and align the left margin of each subsequent line with that
		    of the second line.  This is useful for tagged paragraphs.

	      Split lines only.
		    Do not join short lines to form longer ones.  This prevents sample lines of code, and other such "formatted" text, from  being
		    unduly combined.

	      Fill output lines to up to
		    width columns.

WARNINGS

       The width option is acceptable for BSD compatibility, but it may go away in future releases.

SEE ALSO

       nroff(1), vi(1).

																	    fmt(1)
All times are GMT -4. The time now is 09:06 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy