Sponsored Content
Top Forums UNIX for Beginners Questions & Answers Output of until to file versus stdout Post 303032331 by stomp on Friday 15th of March 2019 09:51:21 AM
Old 03-15-2019
Quote:
Originally Posted by Xubuntu56
Why does this until false; do history | head -5; done
result in a stdout infinite loop, yet until false; do history | head -5 > hist5; done
only writes it once to file hist5? Furthermore, I can hear the hard drive working on the 2nd command until I end the process, but the history | head -5 is only written once.

It does not write once. It writes continously without break the same 5 lines into hist5 file over and over and generates considerable load at your machine. Since every session has its own history this makes no sense to do.


I'm unsure, but I assume .bash_history file is written at logout. If you want to see another sessions history with this, this will not work.
This User Gave Thanks to stomp For This Post:
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

CTRL+H versus ^? versus BACKSPACE

Hi Gurus! I recently got my shell account (HP UX v11) created by our sysadmin and am having problem deleting with the backspace key. After doing some reading, I believe I need to enter a custom "STTY..." statement in my profile. Can someone please help me with the correct "STTY" sequence... (3 Replies)
Discussion started by: alan
3 Replies

2. UNIX for Advanced & Expert Users

sending syslog output to stderr or stdout

Is there a way to send the syslog output for a given facility to stderr or stdout? I do not want to use the "tail" command to achieve this, I would like it to go directly to stderr. Thanks in advance (1 Reply)
Discussion started by: dmirza
1 Replies

3. Shell Programming and Scripting

Script Output Woes (stdout?)

Hey everyone. I have been trying a few filtering scripts with both SED and PERL. So far I have both of these versions working to reformat the incoming text stream (from stdin) into the corrent format (it looks good in the terminal), but I don't think that I am doing it right because the... (2 Replies)
Discussion started by: c0nn0r
2 Replies

4. Shell Programming and Scripting

Dual output (stdout and file)

Hello everybody, Is there a more elegant way to make dual output (display on standard output and append to a file) while I'm executing a shell script, besides duplicating the echo command for every string? echo "Message..." > 1 echo "Message..." >> myfile.out Thank you for your time,... (2 Replies)
Discussion started by: AdrianM
2 Replies

5. Shell Programming and Scripting

let curl output to stdout AND save to a file

hello hackers. i have a curl process running as cgi directly pushing stdout to the client. but i want to additionally save that stream to a file at the same time. any directions madly welcome. thanks in advance (3 Replies)
Discussion started by: scarfake
3 Replies

6. Shell Programming and Scripting

Creating an Array in KSH from output (stdout)

Using Cygwin PDksh - But also have tested it on Linux with same results ---- I have a script that invokes a program/script and returns a string of data (1234 "12 34 56" 6789) and using "set -A" inserting it into an array. script code snipit >> get_array=$(php... (2 Replies)
Discussion started by: carlos25
2 Replies

7. Shell Programming and Scripting

Redirecting part of output to stdout

Hi, I am trying to execute a command like this: find ./ -name "*.gz" -exec sh -c 'zcat {} | awk -f parse.awk' \; >> output If I want to print the filename, i generally use the -print argument to the find command but when I am redirecting the output to a file, how can I print just the... (2 Replies)
Discussion started by: Legend986
2 Replies

8. Programming

Print C file output both in stdout and file

Hello! I want to post a question. does anybody know how to print the output of a C program both in stdout and a file?? thanx (8 Replies)
Discussion started by: nicos
8 Replies

9. Red Hat

CPU usage: PS versus TOP - Different output

CPU usage: PS versus TOP - Different output Hi When monitoring a Linux environment with PS command, reported CPU value for a certain process differs, sometimes greatly, from the value seen in TOP. I understood this is not a bug, they report different data. I can't understand the nature... (4 Replies)
Discussion started by: liav
4 Replies

10. Shell Programming and Scripting

File descriptors, redirecting output, and stdout

Hello all. I've been lurking here for a year or two and finally decided to post. I need some assistance with file descriptors, stdout, and redirecting output. I've searched through a number of very helpful threads here (unfortunately I can't link to any of them yet due to my low post count...),... (2 Replies)
Discussion started by: Michael_K
2 Replies
history(n)					       Provides a history for Entry widgets						history(n)

__________________________________________________________________________________________________________________________________________________

NAME
history - Provides a history for Entry widgets SYNOPSIS
package require Tcl 8.4 package require Tk 8.4 package require history ?0.1? ::history::init pathName ?length? ::history::remove pathName ::history::add pathName text ::history::get pathName ::history::clear pathName ::history::configure pathName option ?value? bell _________________________________________________________________ DESCRIPTION
This package provides a convenient history mechanism for Entry widgets. The history may be accessed with the up and down arrow keys. ::history::init pathName ?length? Arranges to remember the history of the named Entry widget. An optional length determines the number of history entries to keep. This may be changed later with ::history::configure. History entries must be added with the ::history::add command before they can be seen. ::history::remove pathName Forgets all history entries for the Entry pathName and removes the history bindings. ::history::add pathName text This command is used to add history entries to an Entry that has previously had ::history::init called on it. This command should be called from your Entry handler with the contents of the entry (or whatever you wish to add to the history). ::history::get pathName This command returns a list containing the history entries for the Entry pathName ::history::clear pathName This command clears the history list for the named Entry. ::history::configure pathName option ?value? This command queries or sets configuration options. Currently the options recognized are length and alert. Setting the length deter- mines the number of history entries to keep for the named Entry. Alert specifies the command to run when the user reaches the end of the history, it defaults to bell entry .e bind .e <Return> [list ProcessEntry %W] ::history::init .e pack .e proc ProcessEntry {w} { set text [$w get] if {$text == ""} { return } ::history::add $w $text puts $text $w delete 0 end } KEYWORDS
entry, history history 0.1 history(n)
All times are GMT -4. The time now is 12:26 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy