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Full Discussion: Usage of sed, position of apostrophe
Top Forums UNIX for Beginners Questions & Answers Usage of sed, position of apostrophe Post 303022811 by Aia on Friday 7th of September 2018 01:16:17 PM
Old 09-07-2018
Quote:
Originally Posted by baris35
Hello,
I have never ever seen below notation for string substitution.

Code:
sed -i -e 's/tttt/pppp'/g /var/bin/czech.sh;

The strange thing for me is the position of the apostrophe. Should it be before the / or after the g?
If I had been writing that command line, I would have chosen below way:
Code:
sed -i -s 's/tttt/pppp/g' /var/bin/czech.sh

Could you please explain what it differs...
Is that about the operating system?

Many thanks
Boris
Regular expressions uses meta-characters. These are characters that have special meaning beyond the representation of the character. The shell has also meta-characters. Therefore in order to protect the meaning of these characters it must be quoted so it gets passed to sed as the regular expression intended.
In this case the quoting could be avoided all together sed s/tttt/pppp/g /var/bin/czech.sh since there are no meta-characters.
 

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LEARN ABOUT SUNOS

smrsh

smrsh(1M)						  System Administration Commands						 smrsh(1M)

NAME

       smrsh - restricted shell for sendmail

SYNOPSIS

       smrsh  -c command

DESCRIPTION

       The smrsh program is intended as a replacement for the sh command in the prog mailer in sendmail(1M) configuration files. The smrsh program
       sharply limits commands that can be run using the |program syntax of sendmail. This improves overall system security. smrsh limits the  set
       of programs that a programmer can execute, even if sendmail runs a program without going through an alias or forward file.

       Briefly,  smrsh limits programs to be in the directory /var/adm/sm.bin, allowing system administrators to choose the set of acceptable com-
       mands. It also rejects any commands with the characters: ,, <, >, |, ;, &, $, 
 (<RETURN>), or 
 (<NEWLINE>) on the command line to  pre-
       vent end run attacks.

       Initial	pathnames  on  programs  are stripped, so forwarding to /usr/ucb/vacation, /usr/bin/vacation, /home/server/mydir/bin/vacation, and
       vacation all actually forward to/var/adm/sm.bin/vacation.

       System administrators should be conservative about populating /var/adm/sm.bin. Reasonable additions are utilities such as  vacation(1)  and
       procmail.  Never  include  any  shell  or shell-like program (for example, perl) in the sm.bin directory. This does not restrict the use of
       shell or perl scrips in the sm.bin directory (using the #! syntax); it simply disallows the execution of arbitrary programs.

OPTIONS

       The following options are supported:

       -c command

	   Where command is a valid command, executes command.

FILES

       /var/adm/sm.bin	       directory for restricted programs

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsr, SUNWcsu		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       sendmail(1M), , attributes(5)

SunOS 5.10							    6 Nov 1998								 smrsh(1M)
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