Sponsored Content
Top Forums Shell Programming and Scripting Strange Script behaviour with Grep Post 302972307 by RudiC on Wednesday 4th of May 2016 02:41:59 AM
Old 05-04-2016
man bash:
Quote:
QUOTING
Quoting is used to remove the special meaning of certain characters or words to the shell. Quoting can be used to disable special treatment for special characters, to prevent reserved words from being recognized as such, and to prevent parameter expansion.
.
.
.

There are three quoting mechanisms: the escape character, single quotes, and double quotes.

A non-quoted backslash (\) is the escape character. It preserves the literal value of the next character that follows, with the exception of <newline>. If a \<newline> pair appears, and the backslash is not itself quoted, the \<newline> is treated as a line continuation (that is, it is removed from the input stream and effectively ignored).

Enclosing characters in single quotes preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash.

Enclosing characters in double quotes preserves the literal value of all characters within the quotes, with the exception of $, `, \, and, when history expansion is enabled, !. . . .
The last paragraph shows that ' will be preserved literally and NOT used for quoting.

Now, does Don Cragun's post#4 become clearer?


Quote:
Originally Posted by mohtashims
.
.
.
Also, like i said when i manually copy paste this it gives me the output. It fails only when executed from inside the script !!
Difficult to believe. Please execute the exactly identical command from the command line and from within a script, and compare the results.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

A Strange Behaviour!!!

Can some-one give me a view to this : I have a directory in an unix server, having permissions r-xr-xr-x .This directory is basically a source directory. Now there is another directory basically the destination directory which has all the permissions. Note:I log in as not the owner,but user... (5 Replies)
Discussion started by: navojit dutta
5 Replies

2. UNIX for Advanced & Expert Users

Strange sed behaviour

$ echo a.bc | sed -e "s/\|/\\|/g" |a|.|b|c| $ Is the behavior of the sed statement expected ? Or is this a bug in sed ? OS details Linux 2.6.9-55.0.0.0.2.ELsmp #1 SMP Wed May 2 14:59:56 PDT 2007 i686 i686 i386 GNU/Linux (8 Replies)
Discussion started by: vino
8 Replies

3. Shell Programming and Scripting

Strange behaviour from script in crontab

Apologies if this has been mentioned elsewhere, my search skills may be lacking somewhat today. I have a script that does the following (as a test): find . -name "*.txt" -exec file {} \; >>$sFullFilePath Now, the variable is set up up correctly in the script too. When I run the script... (1 Reply)
Discussion started by: PilotGoose
1 Replies

4. UNIX for Dummies Questions & Answers

Strange Program behaviour

Had a strange thing going on with my code. It's ok I figured it out for myself.... (2 Replies)
Discussion started by: mrpugster
2 Replies

5. Shell Programming and Scripting

Expect script strange behaviour

Hi people, I'm having some strange behaviour with an 'expect' script. spawn csession blah expect "Username: " send "userblah\r" expect "Password: " send "passwordblah\r" interact When I execute the script as root it runs perfectly. However, when executed as any other... (0 Replies)
Discussion started by: GarciasMuffin
0 Replies

6. Shell Programming and Scripting

Strange behaviour with perl i/o?

Hi All, I got a strange problem here. I have a perl script which is fetching data from a database table and writing a file with that data. If i run that script from linux command line, the file it creates is a normal ascii text file without any binary character in it.But... (9 Replies)
Discussion started by: DILEEP410
9 Replies

7. Shell Programming and Scripting

Strange RegExp Behaviour

Hello, I was trying to identify lines who has a word of the following pattern "xyyx" (where x, and ys are different characters). I was trying the following grep - egrep '(\S)()\2\1' This pattern do catches the wanted pattern, but it also catches "GGGG" or "CCCC" patterns. I was trying to... (5 Replies)
Discussion started by: itskov
5 Replies

8. Red Hat

Crontab strange behaviour

Hi all, I'm having this scenario which for the moment I cannot resolve. :( I wrote a script to make a dump/export of the oracle database. and then put this entry on crontab to be executed daily for example. The script is like below: cat /home/oracle/scripts/db_backup.sh #!/bin/ksh ... (3 Replies)
Discussion started by: enux
3 Replies

9. Shell Programming and Scripting

strange behaviour script terminate before complete execution

I'm working on a script to make backup of various folder located on various host using different OS. I got a strange behaviour because the script donět process all lines of a configuration file, the script execute only one loop even the input file have 6 lines: This is the script: #!/bin/bash... (4 Replies)
Discussion started by: |UVI|
4 Replies

10. UNIX for Dummies Questions & Answers

Strange behaviour of grep in SunOS

Hi I ahve 2 files with below content: cat file1 FILE3 test1 test2 cat file2 file3 ghg test1 test2 i want to use file1 as pattern file and find out the missing strings in file2.(i.e ghg in this case regardless of c ase) I have tried: grep -i -v -f /path/file1 /path/file2 (6 Replies)
Discussion started by: pandeesh
6 Replies
DATE_DEFAULT_TIMEZONE_SET(3)						 1					      DATE_DEFAULT_TIMEZONE_SET(3)

date_default_timezone_set - Sets the default timezone used by all date/time functions in a script

SYNOPSIS
bool date_default_timezone_set (string $timezone_identifier) DESCRIPTION
date_default_timezone_set(3) sets the default timezone used by all date/time functions. Note Since PHP 5.1.0 (when the date/time functions were rewritten), every call to a date/time function will generate a E_NOTICE if the timezone isn't valid, and/or a E_WARNING message if using the system settings or the $TZ environment variable. Instead of using this function to set the default timezone in your script, you can also use the INI setting date.timezone to set the default timezone. PARAMETERS
o $timezone_identifier - The timezone identifier, like UTC or Europe/Lisbon. The list of valid identifiers is available in the "List of Supported Time- zones". RETURN VALUES
This function returns FALSE if the $timezone_identifier isn't valid, or TRUE otherwise. EXAMPLES
Example #1 Getting the default timezone <?php date_default_timezone_set('America/Los_Angeles'); $script_tz = date_default_timezone_get(); if (strcmp($script_tz, ini_get('date.timezone'))){ echo 'Script timezone differs from ini-set timezone.'; } else { echo 'Script timezone and ini-set timezone match.'; } ?> CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.3.0 | | | | | | | Now throws E_WARNING rather than E_STRICT. | | | | | 5.1.2 | | | | | | | The function started to validate the $time- | | | zone_identifier parameter. | | | | +--------+---------------------------------------------------+ SEE ALSO
date_default_timezone_get(3), "List of Supported Timezones". PHP Documentation Group DATE_DEFAULT_TIMEZONE_SET(3)
All times are GMT -4. The time now is 08:53 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy