07-19-2014
Why would that break old scripts ?
-a and
-o will most likely remain supported by the implementations ...
Obsolescent means that is has become outdated and its usage is discouraged, for the reasons given and there is the intention to remove it from the standard..
Quote:
Q15. Does removal of obsolescent utility syntax mean that implementations supporting usages of head -5 file, tail -5 file, tail -l file are no longer allowed?
No, in general the intent of removing the obsolescent forms of the utility synopses was not to disallow them to be supported by implementations but to downgrade the status of their use in applications from conforming application using an obsolescent feature to non-conforming application. In general it is allowed for utilities to have extensions that violate the utility syntax guidelines so long as the forms defined in the standard that are required to follow the utility syntax guidelines do so. The cases cited fit the case. The Austin Group has more general cases under review at the present time.
POSIX.1 FAQ
---
Quote:
Originally Posted by
techy1
Strange. If i dont use the -o it just doesnt work. Its been a really long time since i had to use -o i forgot about that option
What version of ksh are you using on what OS? Even though older implementations are not POSIX compliant, they should support that syntax..
Last edited by Scrutinizer; 07-19-2014 at 08:41 AM..
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hello,
I am having trouble with the syntax with a conditional statement in a BASH script involving multiple conditions. Any suggestions would be greatly appreciated!
if ; then
array=("${array}" "$dnNum" )
fi
i receive this error:
./testscript: ' (4 Replies)
Discussion started by: grandtheftander
4 Replies
2. Shell Programming and Scripting
Guys, Im trying to have a script that evaluates multiple conditions :
test.sh:
if
then
echo "host $1"
else
if
then
echo "host $1"
else
echo $1 not valid
exit 1
fi
when I do
./test.sh brazil1
I get: (4 Replies)
Discussion started by: bashshadow1979
4 Replies
3. Shell Programming and Scripting
Hi All,
I am new to shell scripting.
Can any one say what is wrong in this if statement, that uses multiple conditions
if
then
***************
else
if ( -z $pcs && "$night_time_calc" > "$night_time" )
then
********************************
... (4 Replies)
Discussion started by: ssenthilkumar
4 Replies
4. Shell Programming and Scripting
how can i specify more than 1 consition in the following AWK statament??
i.e. if $2 is ABCD and $3 is MNOP and $4 is KLPM
similarly for OR
#!/bin/ksh
awk -F '' ' $2 == "ABCD" { print $2, $3;}' file.xml (2 Replies)
Discussion started by: skyineyes
2 Replies
5. Shell Programming and Scripting
Hi,
When i use the below code snippet in my shell script OFC_10.sh:
if
then
echo "Success"
exit 2
elif
then
echo "Failure"
exit 6
I get the error message:
./OFC_10.sh: line 41: '
./OFC_10.sh: line 45: '
Line 41 is the line where If loop starts and line 45 is... (2 Replies)
Discussion started by: shrutihardas
2 Replies
6. UNIX for Dummies Questions & Answers
Deal Experts
I am working on a script to find a date which is 7 days older and follwoing is my approach
#!/bin/sh
Yr=`date +"%Y"`
Mn=`date +"%m"`
Md=28
Da=`date +"%d"`
echo $Yr
echo $Mn
echo $Da
var1=$Yr$Mn$Da
echo "before" $var1
if expr $Da > 7
then Da=`expr $Da - 7`... (3 Replies)
Discussion started by: sweetnsourabh
3 Replies
7. UNIX for Dummies Questions & Answers
Hello Unix-Forums!
It has been a long time since my last post, but finally I've got a new question:
I know in case you can use multiple patterns by
case $var in
a|b|c|ab)
and so on.
But how would I place an OR between
if ]
then
...
if ]
then
...
I want to execute the "..." if... (3 Replies)
Discussion started by: intelinside
3 Replies
8. Shell Programming and Scripting
Fellas,
Am new to unix os/ and here the situation , I am trying to write multiple condition statement inside if but it throws me a error
here is my piece of code ,
if ] && ] && ]
then
commands
fi
error : line 15 : `
can someone please advise me how to fix it
Please use... (7 Replies)
Discussion started by: xeccc5z
7 Replies
9. UNIX for Beginners Questions & Answers
Hi Gurus,
Is there a way we can set a logic for this problem ?
The input file looks like below;
1 15 17
2 8 12
3 18 24
4 21 23
5 2 4
6 11 25
So, I would like to print for any row of the input file where the range of value between $2 to $3 lies within the min and max values of Min=10... (2 Replies)
Discussion started by: Indra2011
2 Replies
10. UNIX for Beginners Questions & Answers
I am analyzing one of the scripts written by another person.script is having multiple if conditions and everything are nested.The code is not formatted properly.Is there any way to identify in Unix to identify begin and end of a particular if block? (6 Replies)
Discussion started by: vamsi.valiveti
6 Replies
TAIL(1) BSD General Commands Manual TAIL(1)
NAME
tail -- display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-q] [-b number | -c number | -n number] [file ...]
DESCRIPTION
The tail utility displays the contents of file or, by default, its standard input, to the standard output.
The display begins at a byte, line or 512-byte block location in the input. Numbers having a leading plus ('+') sign are relative to the
beginning of the input, for example, ``-c +2'' starts the display at the second byte of the input. Numbers having a leading minus ('-') sign
or no explicit sign are relative to the end of the input, for example, ``-n 2'' displays the last two lines of the input. The default start-
ing location is ``-n 10'', or the last 10 lines of the input.
The options are as follows:
-b number
The location is number 512-byte blocks.
-c number
The location is number bytes.
-f The -f option causes tail to not stop when end of file is reached, but rather to wait for additional data to be appended to the
input. The -f option is ignored if the standard input is a pipe, but not if it is a FIFO.
-F The -F option implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The
file is closed and reopened when tail detects that the filename being read from has a new inode number.
If the file being followed does not (yet) exist or if it is removed, tail will keep looking and will display the file from the begin-
ning if and when it is created.
The -F option is the same as the -f option if reading from standard input rather than a file.
-n number
The location is number lines.
-q Suppresses printing of headers when multiple files are being examined.
-r The -r option causes the input to be displayed in reverse order, by line. Additionally, this option changes the meaning of the -b,
-c and -n options. When the -r option is specified, these options specify the number of bytes, lines or 512-byte blocks to display,
instead of the bytes, lines or blocks from the beginning or end of the input from which to begin the display. The default for the -r
option is to display all of the input.
If more than a single file is specified, each file is preceded by a header consisting of the string ``==> XXX <=='' where XXX is the name of
the file unless -q flag is specified.
EXIT STATUS
The tail utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
To display the last 500 lines of the file foo:
$ tail -n 500 foo
Keep /var/log/messages open, displaying to the standard output anything appended to the file:
$ tail -f /var/log/messages
SEE ALSO
cat(1), head(1), sed(1)
STANDARDS
The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification. In particular, the -F, -b and -r
options are extensions to that standard.
The historic command line syntax of tail is supported by this implementation. The only difference between this implementation and historic
versions of tail, once the command line syntax translation has been done, is that the -b, -c and -n options modify the -r option, i.e., ``-r
-c 4'' displays the last 4 characters of the last line of the input, while the historic tail (using the historic syntax ``-4cr'') would
ignore the -c option and display the last 4 lines of the input.
HISTORY
A tail command appeared in PWB UNIX.
BSD
March 16, 2013 BSD