Sponsored Content
Full Discussion: delete all lines in file
Top Forums UNIX for Dummies Questions & Answers delete all lines in file Post 17145 by mikek147 on Monday 11th of March 2002 05:23:03 PM
Old 03-11-2002
touch a_new_empty_file.txt

will create a null file, or will change the last_access_time on that file.

> the_file_I_want_nothing_in.txt

will both empty a full file or create a null file. -mk
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

how can I delete lines without actually going into the file

what am trying to do is delete a line in a specific file but I dont know what to do. I cant use the sed or awk commands because these commands dont really alter the original file. they only alter what they display on the screen by the way, am trying to do this from a script so if anybody can... (5 Replies)
Discussion started by: TRUEST
5 Replies

2. Shell Programming and Scripting

delete lines from a file.

I have a file which has about 500K records and I need to delete about 50 records from the file. I know line numbers and am using sed '13456,13457,......d' filename > new file. It does not seem to be working. Any help will greatly appreciated. (5 Replies)
Discussion started by: oracle8
5 Replies

3. Shell Programming and Scripting

delete the lines from file

i have two files & want to delete the lines from 2nd file which matches with 1st file (2 Replies)
Discussion started by: sameersam
2 Replies

4. Shell Programming and Scripting

delete n last lines of a file

Hello!!! how can I delete the last n lines of a file??? Thanks (7 Replies)
Discussion started by: ncatdesigner
7 Replies

5. Shell Programming and Scripting

How to delete lines in a file that have duplicates or derive the lines that aper once

Input: a b b c d d I need: a c I know how to get this (the lines that have duplicates) : b d sort file | uniq -d But i need opossite of this. I have searched the forum and other places as well, but have found solution for everything except this variant of the problem. (3 Replies)
Discussion started by: necroman08
3 Replies

6. UNIX for Dummies Questions & Answers

How get only required lines & delete the rest of the lines in file

Hiiii I have a file which contains huge data as a.dat: PDE 1990 1 9 18 51 28.90 24.7500 95.2800 118.0 6.1 0.0 BURMA event name: 010990D time shift: 7.3000 half duration: 5.0000 latitude: 24.4200 longitude: 94.9500 depth: 129.6000 Mrr: ... (7 Replies)
Discussion started by: reva
7 Replies

7. UNIX for Advanced & Expert Users

In a huge file, Delete duplicate lines leaving unique lines

Hi All, I have a very huge file (4GB) which has duplicate lines. I want to delete duplicate lines leaving unique lines. Sort, uniq, awk '!x++' are not working as its running out of buffer space. I dont know if this works : I want to read each line of the File in a For Loop, and want to... (16 Replies)
Discussion started by: krishnix
16 Replies

8. UNIX for Dummies Questions & Answers

Delete lines in a file

Hi This is a sample of my data file. ##field PH01000000 1 4869017 #PH01000000G0240 WWW278545G0240 P.he_model_v1.0 erine 119238 121805 . - . ID=PH01000000G0240;Description="zinc finger, C3HC4 type domain containing protein, expressed"... (7 Replies)
Discussion started by: sonia102
7 Replies

9. Shell Programming and Scripting

Delete 40 lines after every 24 lines from a file

Hello, I have file of more than 10000 lines. I want to delete 40 lines after every 20 lines. e.g from a huge file, i want to delete line no from 34 - 74, then 94 - 134 etc and so on. Please let me know how i can do it. Best regards, (11 Replies)
Discussion started by: nehashine
11 Replies

10. UNIX for Beginners Questions & Answers

Delete Some Lines from File

Hi, I have a txt document having a format like this: DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:34 DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:32 DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:30 ... DATA1 | DATA2 | DATA3 | 23-JAN-20 22:35:31 DATA1 | DATA2 | DATA3 | 23-JAN-20 22:30:34 DATA1 | DATA2 |... (1 Reply)
Discussion started by: gc_sw
1 Replies
TOUCH(3)								 1								  TOUCH(3)

touch - Sets access and modification time of file

SYNOPSIS
bool touch (string $filename, [int $time = time()], [int $atime]) DESCRIPTION
Attempts to set the access and modification times of the file named in the $filename parameter to the value given in $time. Note that the access time is always modified, regardless of the number of parameters. If the file does not exist, it will be created. PARAMETERS
o $filename - The name of the file being touched. o $time - The touch time. If $time is not supplied, the current system time is used. o $atime - If present, the access time of the given filename is set to the value of $atime. Otherwise, it is set to the value passed to the $time parameter. If neither are present, the current system time is used. RETURN VALUES
Returns TRUE on success or FALSE on failure. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.3.0 | | | | | | | It became possible to change the modification | | | time of a directory under Windows. | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 touch(3) example <?php if (touch($filename)) { echo $filename . ' modification time has been changed to present time'; } else { echo 'Sorry, could not change modification time of ' . $filename; } ?> Example #2 touch(3) using the $time parameter <?php // This is the touch time, we'll set it to one hour in the past. $time = time() - 3600; // Touch the file if (!touch('some_file.txt', $time)) { echo 'Whoops, something went wrong...'; } else { echo 'Touched file with success'; } ?> NOTES
Note Note that time resolution may differ from one file system to another. Warning Prior to PHP 5.3.0 it was not possible to change the modification time of a directory with this function under Windows. PHP Documentation Group TOUCH(3)
All times are GMT -4. The time now is 09:28 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy