A basic question of FOR loop

Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers A basic question of FOR loop
# 1  
Old 09-28-2007
A basic question of FOR loop

have a basic query.
Please see the below code:

list="one two three"
for var in $list ; do
echo $var

Wht if I want to print only first/ last line in the list

Eg one & three

# 2  
Old 09-28-2007

don't know if it is the best way but awk will work....

echo $variable | awk '{print $1,$NF}'

note $NF represents the no of fields
# 3  
Old 09-28-2007
with zsh and array:

zsh 4.3.4%zsh 4.3.4% list=(one two three)
zsh 4.3.4% print $list[1]
zsh 4.3.4% print $list[-1]


$ list="one two three"
$ printf "${list%% *}\n"
$ printf "${list##* }\n"

# 4  
Old 09-28-2007
with bash
# var=(one two three)
# echo ${var[0]}
# echo ${var[2]}

Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Basic FOR loop with break

Oracle Linux : 6.4/bash shell In the below I want to break out of the loop when it enters the 5th iteration. #!/bin/bash for i in 1 2 3 4 5 6 do echo "$i" if echo "Oh Nooo... i = $i. I need to stop the iteration and jump out of the loop" then break fi done But, it only... (3 Replies)
Discussion started by: John K
3 Replies

2. Shell Programming and Scripting

Basic help improving for in loop

I'm obviously very new to this. I'm trying to write a simple for loop that will read the directory names in /Users and then copy a file into the same subdir in each user directory. I have this, and it works but it isn't great. #!/bin/bash HOMEDIRS=/Users/* for dirs in $HOMEDIRS; do if ];... (5 Replies)
Discussion started by: Heath_T
5 Replies

3. UNIX for Dummies Questions & Answers

Basic loop awk/shell script question..

Hi, Sorry if this is a newbie question. I guess you can use either awk or shell script for this sequence of operations, but knowing very little about either of them I'm not sure how I should try to write this. The basic objective is to copy certain files that are scattered all over my... (10 Replies)
Discussion started by: pc2001
10 Replies

4. Shell Programming and Scripting

Trying to run a basic for loop

OS : RHEL 6.1 Shell : Bash I had a similair post on this a few weeks back. But I didn't explain my requirements clearly then. Hence starting a new thread now. I have lots of files in /tmp/stage directory as show below. I want to loop through each files to run a command on each file. I... (8 Replies)
Discussion started by: kraljic
8 Replies

5. Shell Programming and Scripting

Basic bash, echo in loop for

Hi, I am trying to make a script to manage log. I want to write the name of the .gz I moved and the date : for i in `ls $replog/*.gz` do echo " $i " `echo $i date +%d:%m:%Y` `echo $datee `>> $replog/mrnet.log mv $i /var/log/vieux-logs done I need to echo... (10 Replies)
Discussion started by: Dabless
10 Replies

6. Shell Programming and Scripting

Unix Shell basic loop massive n00b

hey guys I would really appreciate some help, i need to do a project for a job that requires minimal UNIX scripting and im REALLY stuck basically Im stuck at what i believe is something really simple but i just dont have a clue how to do it efficiently and properly and i REALLY appreciate some... (16 Replies)
Discussion started by: thurft
16 Replies

7. Shell Programming and Scripting

Very Basic Question regarding "while" loop

Hi, I have a loop like this - while read item do // fire insert query done < itemList.txt The itemList.txt has say, 1000 records. Now what I do is that rhough another program, I make the itemList.txt EMPTY, but still the INSERT query keeps firing the sequence of records. ... (18 Replies)
Discussion started by: angshuman_ag
18 Replies

8. Shell Programming and Scripting

Basic While loop won't exit...

Hi everyone - just like to say great forum...I've learned a lot off here but I just can't figure this one out...(first post) I'm writing a script to monitor a directory and email the latest modified file....(I realize there are better ways than I'm trying here...I don't like copying and pasting... (5 Replies)
Discussion started by: trevthefatty
5 Replies

9. Shell Programming and Scripting

really basic for loop question

sorry for being dumb here, but is there a way my for loop can take an entire line of a file into consideration instead of each word in a line... ill explain if i have a file like this # cat list serial: 23124 hostname: server1 and a script that does this # cat list.sh #!/bin/sh ... (6 Replies)
Discussion started by: hcclnoodles
6 Replies

10. Shell Programming and Scripting

Basic bash 'for loop' usage

Hi! I have a simple question about using a for loop. I'm trying to open up all the zip files in the currect directory with ark, but I am getting the error "bash: syntax error near unexpected token `for $i ; do ark $i ; done ; I looked in the info pages for bash, but I can't seem to figure... (2 Replies)
Discussion started by: Orange Stripes
2 Replies
Login or Register to Ask a Question