Echo output from command


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Echo output from command
# 1  
Old 12-28-2012
Echo output from command

Hello

i am trying to do some calculation from output command

for example
Code:
ls -l
if [ "$ wc -l" -gt 2 ]
then
echo "error"
else
echo "$"
fi

its something like this
which get strings from output command and try to sum total lines of this string if exceed certain number it display error
if not it display output from the command
please note ls -l is just a example
# 2  
Old 12-28-2012
If I understand what you're trying to do, the following should be the syntax you need:
Code:
if [ "$(ls -l|wc -l)" -gt 2 ]
then
        echo 'error'
else
        echo '$'
fi

This won't display the output from the ls command. If you want to display the output from the ls command, change the
Code:
"$(ls -l|wc -l)"

to:
Code:
"$(ls -l|tee /dev/tty|wc -l)"

I don't understand why you want the echo "$"; it is the default normal user shell prompt and may confuse users if it looks like your script produces two shell prompts.
# 3  
Old 12-28-2012
Quote:
Originally Posted by Don Cragun
If I understand what you're trying to do, the following should be the syntax you need:
Code:
if [ "$(ls -l|wc -l)" -gt 2 ]
then
        echo 'error'
else
        echo '$'
fi

This won't display the output from the ls command. If you want to display the output from the ls command, change the
Code:
"$(ls -l|wc -l)"

to:
Code:
"$(ls -l|tee /dev/tty|wc -l)"

I don't understand why you want the echo "$"; it is the default normal user shell prompt and may confuse users if it looks like your script produces two shell prompts.
hello

i give
Code:
ls -l

as example
but i want general operator that display output from last run command
# 4  
Old 12-28-2012
Quote:
Originally Posted by mogabr
hello

i give
Code:
ls -l

as example
but i want general operator that display output from last run command
So use one of the examples I gave you, but replace ls -l and wc -l with the commands you want to use.

If you would tell us what you really want to do instead of a fake example that reports an error if there is more than one file (with a name not starting with a period (".")) in a directory, we might be able to give you a template that will actually do what you want done.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to echo output of a UNIX command (like ls -l ) using shell script.?

How do i echo the output of a unix command using shell script??? Like: echo /etc/ ls -l (2 Replies)
Discussion started by: sunny2802
2 Replies

2. Shell Programming and Scripting

Need help in echo output

Hi All, I have code to get the UUID and capacity for the LUN from CX -arry. I need the output in this format LUN Number UUID Space in MB LUN 238 60:06:01:60:C2:56:11:00:28:36:67:59:11:04:DE:11 122880 But Now iam getting this... (3 Replies)
Discussion started by: ranjancom2000
3 Replies

3. Shell Programming and Scripting

echo two command output in the same line

Hi, I try to write script and echo two command at the same line . echo "A" echo "B" How can I pipe above two command at the same line in text file . So, in the output text file , you can see below ??? A B not A B Any sugggestion ??? (4 Replies)
Discussion started by: chuikingman
4 Replies

4. Shell Programming and Scripting

problem with suppressed output to file using echo and tee command

Hi, When I run the following command in terminal it works. The string TEST is appended to a file silently. echo TEST | tee -a file.txt &>/dev/null However, when I paste this same line to a file, say shell1.sh, and use bourne shell . I run this file in terminal, ./shell1.sh. However I... (1 Reply)
Discussion started by: shahanali
1 Replies

5. UNIX for Dummies Questions & Answers

Format output from "echo" command

Hi, I have written a BASH shell script that contains a lot of "echo" commands to notify the user about what's going on. The script generates a log file that contains a copy of what is seen in the terminal. The echo statements are generally verbose, and thus extend out for quite a ways on one... (2 Replies)
Discussion started by: msb65
2 Replies

6. Shell Programming and Scripting

Echo and a command's output on the same line

Hello, I'm writing some bash scripts and I'm trying to get an echo command and the output of another command to display on the same line. For example: I want to run echo "Operating System: " unameand have it displayed as Operating System: Darwin Thanks for your help! (7 Replies)
Discussion started by: codyhazelwood
7 Replies

7. Shell Programming and Scripting

weird echo output?

#!/bin/bash INPUT=$1 if then INPUT=0$1 TRACKNUMBER=$INPUT fi TRACKNUMBER=$INPUT echo "Track Number:" $TRACKNUMBER if then echo "File Does Not Exist!: split-track"${TRACKNUMBER}".wav" exit 0 fi CUEFILE="$2" (6 Replies)
Discussion started by: TinCanFury
6 Replies

8. UNIX for Dummies Questions & Answers

What is the output of echo *

Hi all, Kindly let me know the output of echo * command. (4 Replies)
Discussion started by: shailja
4 Replies

9. Shell Programming and Scripting

piping output to echo

Hi, I was wondering why ls * | echo does not print the contents of the directory to the screen? The way I see it, ls * returns a whole lot of information, and then we pipe all this info to echo, so surely it should all come to our screen! Is there a serious flaw in my understanding? ... (3 Replies)
Discussion started by: A1977
3 Replies

10. Shell Programming and Scripting

Store output and Echo

I will admit I am a newbie but I am trying to write some simple scripts Situation: I have a list of IP Addresses that I want to once or 2 times a day store the average ping response time in a database (mysql) I am part way there but not all the way there I have the following cat ./slow... (2 Replies)
Discussion started by: meyerder
2 Replies
Login or Register to Ask a Question

Featured Tech Videos