Thanks guys. Can you briefly explain the curly brackets.
Curly brackets separate the variable name from other text surrounding it. Eg.
means fetch variable foo's value and append it with text bar. Without curly brackets the shell would be searching for a variable called foobar. One could also write
, but that would produce a space between.
# sub: find block (in cols), return line-numbers (begin-end) or 0 if notfound
sub findb{
my ($exp1,$col1,$exp2,$col2)= @_; # $exp = expression to find, $col - column to search in
my $cnt=0;
my ($val1,$val2);
my ($beg,$end);
for($cnt=1;$cnt<=65536;$cnt++){
$val1 =... (3 Replies)
Hi Gurus:
I am trying to understand the following line of code.I did enough of googling to understand but no luck.Please help me understand the follow chunk of code:
X=$0
MOD=${X%/*}/env.ksh
X is the current script from which I am trying to execute.
Say if X=test.ksh
$MOD is echoing :... (3 Replies)
Hi
I have a questions related 2 commands : 'du' and 'ls'.
Why is the difference between output of 'du' and 'ls' cmd's ?
Command 'du' :
------------------
jakubn@server1 /home/jakubn $ du -s *
4 engine.ksh
1331 scripts
'du -s *' ---> shows block count size on disk (512 Bytes... (5 Replies)
Hi all
I stuck with a problem. I want to understand the execution of the below code. Can any one please help me
`sqlplus username/passwd@DB << EOF
set serveroutput on
declare
begin
sql_query;
end;
/
commit
/
quit
EOF`
My ques is why do we use EOF and how does it help. (4 Replies)
Hi,
Please help me to understand the bold segments in the below regex.
Both are of same type whose meaning I am looking for.
find . \( -iregex './\{6,10\}./src' \) -type d -maxdepth 2
Output:
./20111210.0/src
In continuation to above:
sed -e 's|./\(*.\{1,3\}\).*|\1|g'
Output: ... (4 Replies)
Hi Guys,
I am new to scripting , I am trying to rebuild a script based on an old script. Can someone help me figure out what the script is doing? This is only a part of the script.
I am looking to interpret these two points in the scripts:-
1)
test=`echo $?`
while
I do not... (3 Replies)
Hi, I saw the following explanation about alias in bash from gnu website, but I didn't get the meaning:
Bash always reads at least one complete line of input before executing any of the commands on that line.
Aliases are expanded when a command is read, not when it is executed. Therefore, an... (3 Replies)
I tried to use lseek system call to determine the number of bytes in a file. To do so, I used open system call with O_APPEND flag to open a file. As lseek returns the current offset so I called lseek for opened file with offset as zero and whence as SEEK_CUR. So I guess it must return the number of... (3 Replies)
Hi,
I found this in a script and I would like to know how this works
Code is here:
# var1=PART1_PART2
# var2=${var1##*_}
# echo $var2
PART2
I'm wondering how ##* makes the Shell to understand to pick up the last value from the given. (2 Replies)