Sponsored Content
Full Discussion: Speed of mv vs. cp
Top Forums UNIX for Dummies Questions & Answers Speed of mv vs. cp Post 60742 by GMMike on Friday 21st of January 2005 01:25:02 AM
Old 01-21-2005
Speed of mv vs. cp

Hi,
Is mv (move) command quicker than cp (copy command)?

I have large files and I want to know if mv actually copy the data to a new file then deletes the old or whether it just alters information the file system without physically moving data - Unfortuanately I don't have large files to test with...

Thanks.

GMMIKE
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Speed it up!

I wonder, are there any "tricks" to increase my server's access time in general? (4 Replies)
Discussion started by: pappous
4 Replies

2. HP-UX

ftp speed

Background; FTP-ing a small 210K file to a HP7410 attached to a EVA500 the averaging speed 400KB/s FTP-ing a small 210K file to a K570 the average speed is 4500KB/s FTP-ing a 31MB file to a HP7410 attached to a EVA 5000 the average speed is 5500KB/s FTP-ing a 31MB file to a K570 the average... (3 Replies)
Discussion started by: ottof
3 Replies

3. Filesystems, Disks and Memory

dmidecode, RAM speed = "Current Speed: Unknown"

Hello, I have a Supermicro server with a P4SCI mother board running Debian Sarge 3.1. This is the "dmidecode" output related to RAM info: RAM speed information is incomplete.. "Current Speed: Unknown", is there anyway/soft to get the speed of installed RAM modules? thanks!! Regards :)... (0 Replies)
Discussion started by: Santi
0 Replies

4. Shell Programming and Scripting

Optimizing for a Speed-up

How would one go about optimizing this current .sh program so it works at a more minimal time. Such as is there a better way to count what I need than what I have done or better way to match patterns in the file? Thanks, #declare variables to be used. help=-1 count=0 JanCount=0 FebCount=0... (3 Replies)
Discussion started by: switch
3 Replies

5. Shell Programming and Scripting

Processor and Its speed

Hi I need a command to know how many processors are available and what is their speed in UNIX. Thanks (2 Replies)
Discussion started by: diksha2207
2 Replies

6. Filesystems, Disks and Memory

data from blktrace: read speed V.S. write speed

I analysed disk performance with blktrace and get some data: read: 8,3 4 2141 2.882115217 3342 Q R 195732187 + 32 8,3 4 2142 2.882116411 3342 G R 195732187 + 32 8,3 4 2144 2.882117647 3342 I R 195732187 + 32 8,3 4 2145 ... (1 Reply)
Discussion started by: W.C.C
1 Replies

7. Shell Programming and Scripting

How can i speed this script up?

Hi, Im quite new to scripting and would like a bit of assistance with trying to speed up the following script. At the moment it is quite slow.... Any way to improve it? total=111120 while do total=`expr $total + 1` INCREMENT=$total firstline = "blablabla" secondline = "blablabla"... (5 Replies)
Discussion started by: brunlea
5 Replies

8. Programming

malloc vs new speed

Which one is faster among malloc and new? My understanding is that since new also has to call constructors after allocating memory it must be slower than malloc. Am I correct? (1 Reply)
Discussion started by: rupeshkp728
1 Replies

9. Shell Programming and Scripting

Speed Up Grep

Hi, I have to grep string from 20 - 30 files each carries 200 - 300 MB size and append to the file. How to speed the grepping time. cat catalina.out_2012_01_01 | grep "xxxxx" >> backup.txt PLZ, Suggest me, Regards, Nanthagopal A (5 Replies)
Discussion started by: nanthagopal
5 Replies

10. Shell Programming and Scripting

Help me with speed up this script

hey guys i have a perl script wich use to compare hashes but it tookes a long time to do that so i wich i will have the soulition to do it soo fast he is the code <redacted> (1 Reply)
Discussion started by: benga
1 Replies
File::Copy(3pm) 					 Perl Programmers Reference Guide					   File::Copy(3pm)

NAME
File::Copy - Copy files or filehandles SYNOPSIS
use File::Copy; copy("file1","file2") or die "Copy failed: $!"; copy("Copy.pm",*STDOUT); move("/dev1/fileA","/dev2/fileB"); use File::Copy "cp"; $n = FileHandle->new("/a/file","r"); cp($n,"x"); DESCRIPTION
The File::Copy module provides two basic functions, "copy" and "move", which are useful for getting the contents of a file from one place to another. copy The "copy" function takes two parameters: a file to copy from and a file to copy to. Either argument may be a string, a FileHandle reference or a FileHandle glob. Obviously, if the first argument is a filehandle of some sort, it will be read from, and if it is a file name it will be opened for reading. Likewise, the second argument will be written to (and created if need be). Trying to copy a file on top of itself is a fatal error. If the destination (second argument) already exists and is a directory, and the source (first argument) is not a filehandle, then the source file will be copied into the directory specified by the destination, using the same base name as the source file. It's a failure to have a filehandle as the source when the destination is a directory. Note that passing in files as handles instead of names may lead to loss of information on some operating systems; it is recommended that you use file names whenever possible. Files are opened in binary mode where applicable. To get a consistent behaviour when copying from a filehandle to a file, use "binmode" on the filehandle. An optional third parameter can be used to specify the buffer size used for copying. This is the number of bytes from the first file, that will be held in memory at any given time, before being written to the second file. The default buffer size depends upon the file, but will generally be the whole file (up to 2MB), or 1k for filehandles that do not reference files (eg. sockets). You may use the syntax "use File::Copy "cp"" to get at the "cp" alias for this function. The syntax is exactly the same. The behavior is nearly the same as well: as of version 2.15, <cp> will preserve the source file's permission bits like the shell utility cp(1) would do, while "copy" uses the default permissions for the target file (which may depend on the process' "umask", file ownership, inherited ACLs, etc.). If an error occurs in setting permissions, "cp" will return 0, regardless of whether the file was successfully copied. move The "move" function also takes two parameters: the current name and the intended name of the file to be moved. If the destination already exists and is a directory, and the source is not a directory, then the source file will be renamed into the directory specified by the destination. If possible, move() will simply rename the file. Otherwise, it copies the file to the new location and deletes the original. If an error occurs during this copy-and-delete process, you may be left with a (possibly partial) copy of the file under the destination name. You may use the "mv" alias for this function in the same way that you may use the <cp> alias for "copy". syscopy File::Copy also provides the "syscopy" routine, which copies the file specified in the first parameter to the file specified in the second parameter, preserving OS-specific attributes and file structure. For Unix systems, this is equivalent to the simple "copy" routine, which doesn't preserve OS-specific attributes. For VMS systems, this calls the "rmscopy" routine (see below). For OS/2 systems, this calls the "syscopy" XSUB directly. For Win32 systems, this calls "Win32::CopyFile". Special behaviour if "syscopy" is defined (OS/2, VMS and Win32): If both arguments to "copy" are not file handles, then "copy" will perform a "system copy" of the input file to a new output file, in order to preserve file attributes, indexed file structure, etc. The buffer size parameter is ignored. If either argument to "copy" is a handle to an opened file, then data is copied using Perl operators, and no effort is made to preserve file attributes or record structure. The system copy routine may also be called directly under VMS and OS/2 as "File::Copy::syscopy" (or under VMS as "File::Copy::rmscopy", which is the routine that does the actual work for syscopy). rmscopy($from,$to[,$date_flag]) The first and second arguments may be strings, typeglobs, typeglob references, or objects inheriting from IO::Handle; they are used in all cases to obtain the filespec of the input and output files, respectively. The name and type of the input file are used as defaults for the output file, if necessary. A new version of the output file is always created, which inherits the structure and RMS attributes of the input file, except for owner and protections (and possibly timestamps; see below). All data from the input file is copied to the output file; if either of the first two parameters to "rmscopy" is a file handle, its position is unchanged. (Note that this means a file handle pointing to the output file will be associated with an old version of that file after "rmscopy" returns, not the newly created version.) The third parameter is an integer flag, which tells "rmscopy" how to handle timestamps. If it is < 0, none of the input file's timestamps are propagated to the output file. If it is > 0, then it is interpreted as a bitmask: if bit 0 (the LSB) is set, then timestamps other than the revision date are propagated; if bit 1 is set, the revision date is propagated. If the third parameter to "rmscopy" is 0, then it behaves much like the DCL COPY command: if the name or type of the output file was explicitly specified, then no timestamps are propagated, but if they were taken implicitly from the input filespec, then all timestamps other than the revision date are propagated. If this parameter is not supplied, it defaults to 0. Like "copy", "rmscopy" returns 1 on success. If an error occurs, it sets $!, deletes the output file, and returns 0. RETURN
All functions return 1 on success, 0 on failure. $! will be set if an error was encountered. AUTHOR
File::Copy was written by Aaron Sherman <ajs@ajs.com> in 1995, and updated by Charles Bailey <bailey@newman.upenn.edu> in 1996. perl v5.16.2 2012-10-25 File::Copy(3pm)
All times are GMT -4. The time now is 04:09 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy