Sponsored Content
Full Discussion: OR'ing condition in script
Top Forums Shell Programming and Scripting OR'ing condition in script Post 69843 by Just Ice on Wednesday 20th of April 2005 05:57:37 PM
Old 04-20-2005
per the cp man page ...
Quote:
-f Unlink. If a file descriptor for a destination file
cannot be obtained, attempt to unlink the destination
file and proceed.
...

/usr/bin/cp
The following option is supported for /usr/bin/cp only:

-p Preserve. cp duplicates not only the contents of
source_file, but also preserves the owner and group
id, permissions modes, modification and access time,
and ACLs if applicable. Note that the command may fail
if ACLs are copied to a file system that does not sup-
port ACLs. The command will not fail if unable to
preserve modification and access time or permission
modes. If unable to preserve owner and group id, cp
will not fail, and it will clear S_ISUID and S_ISGID
bits in the target. cp will print a diagnostic message
to stderr and return a non-zero exit status if unable
to clear these bits.

In order to preserve the owner and group id, permis-
sion modes, and modification and access times, users
must have the appropriate file access permissions;
this includes being superuser or the same owner id as
the destination file.
however, i've never really used the "-f" option --- like most other esoteric options of other commands that are good to know but not required for basic stuff --- so i don't actually understand the unlink statement ... maybe one of the hardcore c programmers here can explain it better ...

do look at this test here and you can decide what it is you need ...
Code:
root_mybox:/tmp # cp -p /etc/profile testprofile
root_mybox:/tmp # ls -l /etc/profile testprofile
-rw-r--r--   1 root     sys          920 Dec  3 19:04 /etc/profile
-rw-r--r--   1 root     sys          920 Dec  3 19:04 testprofile
root_mybox:/tmp # cp -f /etc/profile testprofile1
root_mybox:/tmp # ls -l /etc/profile testprofile1
-rw-r--r--   1 root     sys          920 Dec  3 19:04 /etc/profile
-rw-r--r--   1 root     other        920 Apr 20 17:51 testprofile1
root_mybox:/tmp #

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

IF condition failing in a SSH script

Hi, I'm ssh-in to a remote machine (ubuntu) and trying to execute a little script in there.The script looks like this: ssh user@ubuntu <<EOF cd ~/test ls -l echo "Continue counting files starting with a`s ?" read answer if then ls -l a* else exit fi EOF Now everything works... (9 Replies)
Discussion started by: rubionis
9 Replies

2. Shell Programming and Scripting

grep'ing and sed'ing chunks in bash... need help on speeding up a log parser.

I have a file that is 20 - 80+ MB in size that is a certain type of log file. It logs one of our processes and this process is multi-threaded. Therefore the log file is kind of a mess. Here's an example: The logfile looks like: "DATE TIME - THREAD ID - Details", and a new file is created... (4 Replies)
Discussion started by: elinenbe
4 Replies

3. Shell Programming and Scripting

Condition in script

Hi all, I am writing a script (.sh) which takes backup of database, zip it ftp to remote server and finally mail me to notify. So far this all has been done, however, now I am looking to add notification over each step. Means if any step is failed, then I should get an email and if all goes... (2 Replies)
Discussion started by: viki250
2 Replies

4. Shell Programming and Scripting

Script printing else condition

Please help what is wrong in below script. It is printing else also, else echo "DATABASE NOT RUNNING :${i} ================================================= #!/usr/bin/ksh set -A DBS $(cat /etc/oratab | grep ":Y" | awk -F : '{print $1}') set -A RDBS $(ps -ef | grep -i pmon | grep... (3 Replies)
Discussion started by: allwin
3 Replies

5. Shell Programming and Scripting

redirect stdout echo command in condition A run in condition B

hi, I have some problems in my simple script about the redirect echo stdout command inside a condition. Why is the echo command inside the elif still execute in the else command Here are my simple script After check on the two diff output the echo stdout redirect is present in two diff... (3 Replies)
Discussion started by: jao_madn
3 Replies

6. Shell Programming and Scripting

Script with variable and condition

Hello newbies question... I just need a script able to launch a command when a condition is matched : #!/bin/ksh SIZ = 'cat /nurp/control.lst|wc -l' if test "$SIZ" -gt 0 then echo 1 else echo 2 fi but I receive errors messages ./t2: SIZ: not found 2 whats wrong ? (5 Replies)
Discussion started by: vdurieu
5 Replies

7. UNIX for Dummies Questions & Answers

While condition in shell script

while do if ;then read driverName else driverName="" fi done can anyone please explain what exactly is happening on 1st line...is it like the conditions being ORed...I have no clue about this. (4 Replies)
Discussion started by: rtagarra
4 Replies

8. Shell Programming and Scripting

If condition return 0 even when it fails to satisfy te condition

HI My doubt may be basic one but I need to get it clarified.. When i use "if" condition that checks for many AND, OR logical conditions like if ]; then return 0 fi Even the if condition fails it returns as zero.. Any clue.. But if i add else condition like if ]; ... (2 Replies)
Discussion started by: Priya Amaresh
2 Replies

9. Shell Programming and Scripting

Creating a condition on a bash script

I wrote a code to find codons in a DNA string. The only problem I have is how do I make the code only work for a file with DNA. This means the file only has the characters a,c,g,t and no white space characters. (3 Replies)
Discussion started by: germany1517
3 Replies

10. UNIX for Beginners Questions & Answers

Condition in bash script

I want get from user and pass these parameters to bash script. script should copy files in user home directory. FYI: each file might be exist or not, might be one of them exist or four of them. Here is my script, it always copy file1 and seems only one of them execute! #!/bin/bash for... (6 Replies)
Discussion started by: indeed_1
6 Replies
CP(1)							    BSD General Commands Manual 						     CP(1)

NAME
cp -- copy files SYNOPSIS
cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file target_file cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file ... target_directory DESCRIPTION
In the first synopsis form, the cp utility copies the contents of the source_file to the target_file. In the second synopsis form, the con- tents of each named source_file is copied to the destination target_directory. The names of the files themselves are not changed. If cp detects an attempt to copy a file to itself, the copy will fail. The following options are available: -H If the -R option is specified, symbolic links on the command line are followed. (Symbolic links encountered in the tree traversal are not followed.) -L If the -R option is specified, all symbolic links are followed. -P If the -R option is specified, no symbolic links are followed. This is the default. -R If source_file designates a directory, cp copies the directory and the entire subtree connected at that point. If the source_file ends in a /, the contents of the directory are copied rather than the directory itself. This option also causes symbolic links to be copied, rather than indirected through, and for cp to create special files rather than copying them as normal files. Created directo- ries have the same mode as the corresponding source directory, unmodified by the process' umask. Note that cp copies hard linked files as separate files. If you need to preserve hard links, consider using tar(1), cpio(1), or pax(1) instead. -a Archive mode. Same as -RpP. -f For each existing destination pathname, remove it and create a new file, without prompting for confirmation regardless of its permis- sions. (The -f option overrides any previous -i or -n options.) -i Cause cp to write a prompt to the standard error output before copying a file that would overwrite an existing file. If the response from the standard input begins with the character 'y' or 'Y', the file copy is attempted. (The -i option overrides any previous -f or -n options.) -l Create hard links to regular files in a hierarchy instead of copying. -n Do not overwrite an existing file. (The -n option overrides any previous -f or -i options.) -p Cause cp to preserve the following attributes of each source file in the copy: modification time, access time, file flags, file mode, ACL, user ID, and group ID, as allowed by permissions. If the user ID and group ID cannot be preserved, no error message is displayed and the exit value is not altered. If the source file has its set-user-ID bit on and the user ID cannot be preserved, the set-user-ID bit is not preserved in the copy's permissions. If the source file has its set-group-ID bit on and the group ID cannot be preserved, the set-group-ID bit is not pre- served in the copy's permissions. If the source file has both its set-user-ID and set-group-ID bits on, and either the user ID or group ID cannot be preserved, neither the set-user-ID nor set-group-ID bits are preserved in the copy's permissions. -v Cause cp to be verbose, showing files as they are copied. -x File system mount points are not traversed. For each destination file that already exists, its contents are overwritten if permissions allow. Its mode, user ID, and group ID are unchanged unless the -p option was specified. In the second synopsis form, target_directory must exist unless there is only one named source_file which is a directory and the -R flag is specified. If the destination file does not exist, the mode of the source file is used as modified by the file mode creation mask (umask, see csh(1)). If the source file has its set-user-ID bit on, that bit is removed unless both the source file and the destination file are owned by the same user. If the source file has its set-group-ID bit on, that bit is removed unless both the source file and the destination file are in the same group and the user is a member of that group. If both the set-user-ID and set-group-ID bits are set, all of the above conditions must be fulfilled or both bits are removed. Appropriate permissions are required for file creation or overwriting. Symbolic links are always followed unless the -R flag is set, in which case symbolic links are not followed, by default. The -H or -L flags (in conjunction with the -R flag) cause symbolic links to be followed as described above. The -H, -L and -P options are ignored unless the -R option is specified. In addition, these options override each other and the command's actions are determined by the last one specified. If cp receives a SIGINFO (see the status argument for stty(1)) signal, the current input and output file and the percentage complete will be written to the standard output. EXIT STATUS
The cp utility exits 0 on success, and >0 if an error occurs. EXAMPLES
Make a copy of file foo named bar: $ cp foo bar Copy a group of files to the /tmp directory: $ cp *.txt /tmp Copy the directory junk and all of its contents (including any subdirectories) to the /tmp directory: $ cp -R junk /tmp COMPATIBILITY
Historic versions of the cp utility had a -r option. This implementation supports that option, however, its behavior is different from his- torical FreeBSD behavior. Use of this option is strongly discouraged as the behavior is implementation-dependent. In FreeBSD, -r is a syn- onym for -RL and works the same unless modified by other flags. Historical implementations of -r differ as they copy special files as normal files while recreating a hierarchy. The -v and -n options are non-standard and their use in scripts is not recommended. SEE ALSO
mv(1), rcp(1), umask(2), fts(3), symlink(7) STANDARDS
The cp command is expected to be IEEE Std 1003.2 (``POSIX.2'') compatible. HISTORY
A cp command appeared in Version 1 AT&T UNIX. BSD
March 15, 2013 BSD
All times are GMT -4. The time now is 04:55 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy