FTP multiple files without prompt

I knew there was a way to ftp multiple files without being prompted.
It was just a matter of knowing the syntax.

It is possible to download several files at once, using the mget command. This command can take several filenames as arguments, and you can even use wildcards to download matching files. For example, the command


mget *.txt


would download all the files that end in .txt in the current directory on the remote host. When using mget , you will be prompted as to whether or not you wish to download each file. This feature can be toggled on and off by typing prompt at the ftp> prompt before beginning the file transfer.

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Manage directory navigation with pushd and popd

UNIX supports a wide variety of directory-navigation tools. Two good tools are pushd and popd.

You're certainly aware that the cd command changes your current directory. What happens if you have several directories to navigate, but you want to be able to quickly return to a location? The pushd and popd commands create a virtual directory stack, with the pushd command changing your current directory and storing it on the stack, and the popd command removing the directory from the top of the stack and returning you to that location. You can use the dirs command to display the current directory stack without pushing or popping a new directory. Listing below shows how you can use the pushd and popd commands to quickly navigate the directory tree.

$ pushd .
~ ~
$ pushd /etc
/etc ~ ~
$ pushd /var
/var /etc ~ ~
$ pushd /usr/local/bin
/usr/local/bin /var /etc ~ ~
$ dirs
/usr/local/bin /var /etc ~ ~
$ popd
/var /etc ~ ~
$ popd
/etc ~ ~
$ popd
~ ~
$ popd

The pushd and popd commands also support parameters to manipulate the directory stack. Using the +n or -n parameter, where n is a number, you can rotate the stack left or right, as shown below

$ dirs
/usr/local/bin /var /etc ~ ~
$ pushd +1
/var /etc ~ ~ /usr/local/bin
$ pushd -1
~ /usr/local/bin /var /etc ~

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Reuse previous arguments

Here is another great tip from IBM. I love this. The !$ command returns the last argument used with a command. But what happens if you have a command that used arguments and you want to reuse just one of them?

The !:1 operator returns the argument used in a command. The example in Listing 3 shows how you can use this operator in combination with the !$ operator. In the first command, a file is renamed to a more meaningful name, but to preserve use of the original file name, a symbolic link is created. The file kxp12.c is renamed in a more readable manner, then the link command is used to create a symbolic link back to the original file name, in case it's still used elsewhere. The !$ operator returns the file_system_access.c argument, and the !:1 operator returns the kxp12.c argument, which is the first argument of the previous command.

$ mv kxp12.c file_system_access.c
$ ln –s !$ !:1

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Use history expansion

This post is from Unix tips from IBM. What happens if you're using the same file name for a series of commands? Well, there's a shortcut that can quickly retrieve the last file name you used.

What happens if you're using the same file name for a series of commands? Well, there's a shortcut that can quickly retrieve the last file name you used. As shown below, the !$ command returns the file name that the previous command used. The file this-is-a-long-lunch-menu-file.txt is searched for occurrences of the word pickles. After searching, the vi command is used to edit the this-is-a-long-lunch-menu-file.txt file without the need for retyping the file name. You use the bang, or exclamation point (!), to access the history, and the dollar sign ($) returns the last field of the previous command. It's a great tool if you are using long file names repeatedly.

$ grep pickles this-is-a-long-lunch-menu-file.txt
pastrami on rye with pickles and onions
$ vi !$

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Redirect stdout and stderr to same file

I keep forgetting the correct syntax....

% script 2>& logfile
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More unix find tips

There are so many little things to remember in this command that I always have to lookup what switches to use. So here are a few ways of using find


To find all files modified in the last 24 hours (last full day) in current directory and its sub-directories:

find . -mtime -1 -print

Flag -mtime -1 option tells find command to look for files modified in the last day (24 hours). Flag -print option will cause find command to print the files’ location. -print can be replaced with -ls if you want a directory-listing-type response.

To find all files modified in the last 24 hours (last full day) in a particular specific directory and its sub-directories:

find /directory_path -mtime -1 -print

The command is basically the same with the earlier command, just that now you no need to cd (change directory) to the directory you want to search.

To find all files with regular file types only, and modified in the last 24 hours (last full day) in current directory and its sub-directories:

find /directory_path -type f -mtime -1 -print

To find all files that are modified today only (since start of day only, i.e. 12 am), in current directory and its sub-directories:

touch -t `date +%m%d0000` /tmp/$$
find /tmefndr/oravl01 -type f -newer /tmp/$$
rm /tmp/$$

The first command can be modified to specify other date and time, so that the commands will return all files that have changed since that particular date and time.

Find a file or directory
# find . -name TEMP -print
or
# find . -name TEMP -exec echo {} \;

Find core files in this directory tree and remove them
# find . -name "core" -exec rm -f {} \;

Find junk directories and remove their contents recursively
# find . -name "junk" -exec rm -rf {} \;

Find a pattern in a file using the recursive grep (ignore case)
# find . -type f xargs grep -i MYPATTERN

Find files modified in the past 7 days
# find . -mtime -7 -type f

Find files owned by a particular user
# find . -user esofthub

Find all your writable directories and list them
# find . -perm -0777 -type d -lsor# find . -type d -perm 777 -print

Find all your writable files and list them
# find . -perm -0777 -type f -lsor#find . -type f -perm 777 -print

Find large file sizes and list them
# find . -type f -size +1000 -lsor
# find . -type f -size +1000 -print

Find how many directories are in a path (counts current directory)
# find . -type d -exec basename {} \; wc -l
53

Find how many files are in a path
# find . -type f -exec basename {} \; wc -l
120

Find all my pipe files and change their permissions to all writable
# find . -name "pipe*" -exec chmod 666 {} \;

Find files that were modified 7 days ago and archive
# find . -type f -mtime 7 xargs tar -cvf `date '+%d%m%Y'_archive.tar`

Find files that were modified more than 7 days ago and archive
# find . -type f -mtime +7 xargs tar -cvf `date '+%d%m%Y'_archive.tar`

Find files that were modified less than 7 days ago and archive
# find . -type f -mtime -7 xargs tar -cvf `date '+%d%m%Y'_archive.tar`

Find files that were modified more than 7 days ago but less than 14 days ago and archive
# find . -type f -mtime +7 -mtime -14 xargs tar -cvf `date '+%d%m%Y'_archive.tar`

Find files in two different directories having the "test" string and list them
# find esofthub esoft -name "*test*" -type f -ls

Find files in two different directories having the "test" string and list them
# find esofthub esoft -name "*test*" -type f -ls

Find files in two different directories having the "test" string and count them
# find esofthub esoft -name "*test*" -type f -ls wc -l
12

Find files and directories newer than CompareFile
# find . -newer CompareFile -print

Find files and directories older than CompareFile
# find . ! -newer CompareFile -print

Find files and directories but don't traverse a particular directory
# find . -name RAID -prune -o -print

Find all the files in the current directory
# find * -type f -print -o -type d -prune

Find an inode and remove
# find . -inum 968746 -exec rm -i {} \;

Avoid using "-exec {}", as it will fork a child process for every file, wasting memory and CPU in the process. Use `xargs`, which will celeverly fit as many arguments as possible to feed to a command, and split up the number of arguments into chunks as necessary:

find . -depth -name "blabla*" -type f xargs rm -f

Also, be as precise as possible when searching for files, as this directly affects how long one has to wait for results to come back. Most of the stuff actually only manipulates the parser rather than what is actually being searched for, but even there, we can squeeze some performance gains, for example:
- use "-depth" when looking for ordinary files and symollic links, as "-depth" will show them before directories
- use "-depth -type f" when looking for ordinary file(s), as this speeds up the parsing and the search significantly:

find . -depth -type f -print ...

- use "-mount" as the first argument when you know that you only want to search the current filesystem, and
- use "-local" when you want to filter out the results from remote filesystems.
Note that "-local" won't actually cause `find` not to search remote file systems -- this is one of the options that affects parsing of the results, not the actual process of locating files; for not spanning remote filesystems, use "-mount" instead:

find / -mount -depth \( -type f -o -type l \) -print ...


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Copy and paste in Vi/Vim

This is a neat trick to know and saves a lot of time:

1. Go to the beginning of the line where you want to start copying.
2. Make sure you are in the command mode. (Hit ESC).
3. Type "ma". Which means, you are marking the spot with "a".
4. Go to the line till where you want to copy.
5. type y`a (yank to mark a). The ` is the back tick.
6. Now go to the place where you want to paste the text.
7. type p

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Tips on unix find

Here is a nice tip on unix find..

$ find . cpio -pdumv /path/to/destination/dir

the files found by find are passed into cpio and it copies the files with the same permissions to the destination directory.
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linux tip on tar

If you untar a package, and it makes a mess of your directory because the packager didn't include the files in his tarball in a directory, you can use

% rm `tar ftz package.tar.gz`

to quickly get rid of those cluttering files.

% rm `tar ft package.tar`

does the same thing.


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