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Full Discussion: SED help (remove line::parse again::add line)
Top Forums Shell Programming and Scripting SED help (remove line::parse again::add line) Post 302142031 by bakunin on Wednesday 24th of October 2007 02:56:15 AM
Old 10-24-2007
I suspect the problem to be the following:

After changing the file /home/$usrName/.facet and writing the results to /home/testdir/$usrName (so far ok) you try to modify this file writing back to it immediately. This is FORBITTEN! Something like

sed 's/this/that' file > file.new

works, but

sed 's/this/that' file > file

won't. The reason is: sed will read the first line of the input file (which is "file"), apply any rules that might be applicable and then write the result (the changed or not changed line) to <stdout>. This <stdout> is at this moment pointing to "file" and this is why after the first line the file will contain nothing more than exactly that first line - so sed encounters the EOF and thinks it is finished. In the first example it is not writing back to its input file but some other file "file.new", which is why there is no problem.

There is another (perhaps minor) detail i found: You read from keyboard a variable "usrList" and do nothing with it. Why?

bakunin
 

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LEARN ABOUT SUNOS

gshadow

GSHADOW(5)                                                 File Formats and Conversions                                                 GSHADOW(5)

NAME

       gshadow - shadowed group file

DESCRIPTION

       /etc/gshadow contains the shadowed information for group accounts.

       This file must not be readable by regular users if password security is to be maintained.

       Each line of this file contains the following colon-separated fields:

       group name
           It must be a valid group name, which exist on the system.

       encrypted password
           Refer to crypt(3) for details on how this string is interpreted.

           If the password field contains some string that is not a valid result of crypt(3), for instance ! or *, users will not be able to use a
           unix password to access the group (but group members do not need the password).

           The password is used when a user who is not a member of the group wants to gain the permissions of this group (see newgrp(1)).

           This field may be empty, in which case only the group members can gain the group permissions.

           A password field which starts with an exclamation mark means that the password is locked. The remaining characters on the line
           represent the password field before the password was locked.

           This password supersedes any password specified in /etc/group.

       administrators
           It must be a comma-separated list of user names.

           Administrators can change the password or the members of the group.

           Administrators also have the same permissions as the members (see below).

       members
           It must be a comma-separated list of user names.

           Members can access the group without being prompted for a password.

           You should use the same list of users as in /etc/group.

FILES

       /etc/group
           Group account information.

       /etc/gshadow
           Secure group account information.

SEE ALSO

       gpasswd(5), group(5), grpck(8), grpconv(8), newgrp(1).

shadow-utils 4.5                                                    01/25/2018                                                          GSHADOW(5)
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