No. The ! keyword in the shell doesn't MEAN anything. It DOES something. As I said before, it "reverses the exit status of the given command (tar in this case) so that if the command fails (exits with a non-zero exit status) it will execute the then clause and if the command succeeds (i.e., exits with zero exit status) it will execute the else clause if there is one.
Look at each of the following if statements and try to determine what the output will be. Then run the command and see if it did what you expected:
Code:
if true; then echo then; else echo else; fi
if ! true; then echo then; else echo else; fi
if ! ! true; then echo then; else echo else; fi
if false; then echo then; else echo else; fi
if ! false; then echo then; else echo else; fi
if ! ! false; then echo then; else echo else; fi
Hi.
I'm trying to copy multiple folders from the remote machine to the local machine. I wrote a batch file to run an ftp window.
The problem I am having is that the only command to copy files is mget *, and this copies only files, not folders.
For example, ftp ts555
cd ts555/test
' test... (5 Replies)
I have written a shell script to perform backups using tar, rsync and optionally utilise lvm snapshots. The script is not finished but is in a working state and comments/descriptions are poor.
I would greatly appreciate any criticism and suggestions of the script to help improve my own learning... (0 Replies)
I have in directory /media/AUDIO/WAVE many .mp3 files with names like:
my filename_01of02.mp3
my filename_02of02.mp3
Your File_01of06.mp3
Your File_02of06.mp3
etc....
In the same directory, /media/AUDIO/WAVE, I have many folders with names like
9780743579490
9780743579491
etc..
Inside... (7 Replies)
I have 1000's of directories which is named as numbers. Each directory contains multiple files. Each of these directories have a file named "att". I need to rename all the att files by adding the directory name followed by "_" then att for each of the directories.
Directories
120
att... (2 Replies)
Hi all,
I have a tar file and inside that tar file is a folder with additional tar.gz files. What I want to do is look inside the first tar file and then find the second tar file I'm looking for, look inside that tar.gz file to find a certain directory. I'm encountering issues by trying to... (1 Reply)
I would like to confirm my file.tar is been tar-ed correctly before I remove them. But I have very limited disc space to untar it.
Can I just do the listing instead of actual extract it? Can I say confirm folder integrity if the listing is sucessful without problem?
tar tvf file1.tar
... (1 Reply)
Hi All,
I have to requirement to write a shell script to move file from one folder (A) to another five folder (B,C,D,E,F) and destination folder should be blank. In not blank just skip.
This script will run as a scheduler every 2 minutes. It will check number of files in folder A and move 1 to... (9 Replies)
Good day, everyone!
I'm very new to bash scripting. Our teacher gave us a task to create a script that basically does the same job the 'du' command does, with the difference that 'du' command gives an output in the form of
<size> <folder name>and what we need is
<folder name> <size>As for... (1 Reply)
1. The problem statement, all variables and given/known data:
The task is to create a script that would reproduce the output of 'du' command, but in a different way: what 'du' does is:
<size> <folder name>and what is needed is
<folder name> <size>We need to show only 10 folders which are the... (3 Replies)
HI Guys,
I have some 8 files with different name and extensions. I need to check if they are present in a specific folder or not and also want that script to show me which all are not present. I can write if condition for each file but from a developer perspective , i feel that is not a good... (3 Replies)
Discussion started by: shankarpanda003
3 Replies
LEARN ABOUT PHP
echo
ECHO(3) 1 ECHO(3)echo - Output one or more stringsSYNOPSIS
void echo (string $arg1, [string $...])
DESCRIPTION
Outputs all parameters.
echo is not actually a function (it is a language construct), so you are not required to use parentheses with it. echo (unlike some other
language constructs) does not behave like a function, so it cannot always be used in the context of a function. Additionally, if you want
to pass more than one parameter to echo, the parameters must not be enclosed within parentheses.
echo also has a shortcut syntax, where you can immediately follow the opening tag with an equals sign. Prior to PHP 5.4.0, this short syn-
tax only works with the short_open_tag configuration setting enabled.
I have <?=$foo?> foo.
PARAMETERS
o $arg1
- The parameter to output.
o $...
-
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
echo examples
<?php
echo "Hello World";
echo "This spans
multiple lines. The newlines will be
output as well";
echo "This spans
multiple lines. The newlines will be
output as well.";
echo "Escaping characters is done "Like this".";
// You can use variables inside of an echo statement
$foo = "foobar";
$bar = "barbaz";
echo "foo is $foo"; // foo is foobar
// You can also use arrays
$baz = array("value" => "foo");
echo "this is {$baz['value']} !"; // this is foo !
// Using single quotes will print the variable name, not the value
echo 'foo is $foo'; // foo is $foo
// If you are not using any other characters, you can just echo variables
echo $foo; // foobar
echo $foo,$bar; // foobarbarbaz
// Some people prefer passing multiple parameters to echo over concatenation.
echo 'This ', 'string ', 'was ', 'made ', 'with multiple parameters.', chr(10);
echo 'This ' . 'string ' . 'was ' . 'made ' . 'with concatenation.' . "
";
echo <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon. no extra whitespace!
END;
// Because echo does not behave like a function, the following code is invalid.
($some_var) ? echo 'true' : echo 'false';
// However, the following examples will work:
($some_var) ? print 'true' : print 'false'; // print is also a construct, but
// it behaves like a function, so
// it may be used in this context.
echo $some_var ? 'true': 'false'; // changing the statement around
?>
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
SEE ALSO print(3), printf(3), flush(3), Heredoc syntax.
PHP Documentation Group ECHO(3)