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Full Discussion: Bash : Why are spaces important here ?
Top Forums Shell Programming and Scripting Bash : Why are spaces important here ? Post 302932225 by balajesuri on Tuesday 20th of January 2015 05:02:05 AM
Old 01-20-2015
Quote:
Originally Posted by John K
BTW ..What is ++ operator as in (( ++count )) called ?
It's known as a pre-increment operator. It means, first increment the value in count and then use it.
On the contrary, there's a post-increment operator ((count++)); which means use it first and then increment it.

It will be clear in the following example:
Code:
[user@host ~]$ x=1
[user@host ~]$ y=$((++x))
[user@host ~]$ echo $x $y
2 2
[user@host ~]$ x=1
[user@host ~]$ y=$((x++))
[user@host ~]$ echo $x $y
2 1
[user@host ~]$

These 2 Users Gave Thanks to balajesuri For This Post:
John K rbatte1
 

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LEARN ABOUT ULTRIX

hosts.equiv

hosts.equiv(5)							File Formats Manual						    hosts.equiv(5)

Name
       hosts.equiv - list of trusted hosts

Description
       The file resides in the directory and contains a list of trusted hosts.	When an or request from a host listed in the file is made, and the
       initiator of the request has an entry in further validity checking is not required.  Thus, does not prompt for a  password,  and  completes
       successfully.  When a remote user is in the local file, that user is defined as equivalenced to a local user with the same user ID.

       The format of is a list of names, as in:
       host1
       -host2
       +@group1
       -@group2

       A  line	consisting  of a host name means that anyone logging in from that host is trusted.  A line consisting of a host name preceded by -
       means that anyone logging in from that host is not trusted.  A line consisting of a single + means that all hosts are trusted.	Placing  a
       line consisting of a single + in your file poses substantial security risks and is not recommended.

       The  +@ and -@ syntax are specific to Yellow Pages (YP).  A line consisting of +@group means that all hosts in that network group (which is
       served by YP) are trusted.  A line consisting of -@group means that hosts in that network group (which is served by YP)	are  not  trusted.
       Programs  scan  the  file sequentially and stop when they encounter the appropriate entry (either positive for host name and +@ entries, or
       negative for -@ entries).

       The file has the same format as the file.  When a user executes or the file from that user's home directory is concatenated onto  the  file
       for  permission	checking.  The host names listed in the and files may optionally contain the local BIND domain name.  For more information
       on BIND, see the Guide to the BIND/Hesiod Service.  If a user is excluded by a minus entry from but included in	that  user  is	considered
       trusted.  In the special case when the user is root, only the file is checked.

       It  is  possible to have two entries on a single line.  Separate the entires with a space.  If the remote host is equivalenced by the first
       entry, the user named by the second entry is allowed to specify any name to the option (provided that name is in the file).  For example:
       suez john
       This entry allows John to log in from suez.  The normal use would be to put this entry in the file in the home directory for  bill.   Then,
       John can log in as bill when coming from suez without having to supply a password.  The second entry can be a netgroup.	For example:
       +@group1 +@group2
       This entry allows any user in group2 coming from a host in group1 to log in as anyone.

Files
       /var/yp/domain/netgroup
       /var/yp/domain/netgroup.byuser
       /var/yp/domain/netgroup.byhost

See Also
       rlogin(1c), rsh(1c), netgroup(5yp)
       Guide to the BIND/Hesiod Service
       Guide to the Yellow Pages Service

																    hosts.equiv(5)
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