These are regular expressions. * means zero or more spaces \. and \$ mean a literal dot and a literal dollar sign / .... / these two slashes are not part of a regular expression, but rather demarcate it and are part of the awk syntax..
So for example the first regular expression used is
With first character being a space..
About associative nature of awk arrays i'm still confused, not able to understand yet how array element can be accessed based on a string, I got one example at gawk manual to illustrate associative nature of awk arrays, it goes here:
Codeawk '
# Print list of word frequencies
{
for (i = 1;... (3 Replies)
i am not able to understand the following code for awk:
$awk -F"|" '{ kount++}
>END { for (desig in kount)
> print desig,kount }' emp.list
the input file i.e. emp.list is ::
3432| p.k.agrwal |g.m |sales
4566|g.l.sharma |director|production
3433|r shah | g.m | production... (1 Reply)
Hi
I am unable to understand the disk layout of one of my disk attached to v240. This is newly installed system from jumpstart.
I am unable to see the free space on backup slice 2 and there are 0 to 8 slices listed when I run format and print the disk info, also there is no reference of... (9 Replies)
Hi Guys,
Can someone please explain this code to me. I could figure out it's adding and comparing two fields but I am not sure which ones.
sort -t"|" -k3.1 /tmp/mpcashqc.xtr| awk -F"|" '{CHECKAMT+=$3;BATCHTOT=$4;\
items++}END{for(i in CHECKAMT) if (CHECKAMT!=BATCHTOT)... (6 Replies)
I m executing ps command and sorting it according to memory usage.
Please find the output of the command.
# ps aux --sort pmem
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 2060 624 ? Ss 01:54 0:00 init
root 2 0.0... (1 Reply)
Hi geeks,
I am trying to understand below if statement. can someone please explain me meaning of if condition.
if ]
then
echo -e "1"
fi
Thanks
Please use CODE tags. (3 Replies)
Discussion started by: jagnikam
3 Replies
7. Post Here to Contact Site Administrators and Moderators
Variable I have in my shell script
diff=$1$2.diff
id=$2
new=new_$diff
echo "My id is $1"
echo "I want to sync for user account $id"
##awk command I am using is as below
cat $diff | awk -F'~' ''$2 == "$id"' {print $0}' > $new
I could see value of $id is not passing to the awk... (0 Replies)
I have a shell script (.sh) and I want to pass a parameter value to the awk command but I am getting exception, please assist.
diff=$1$2.diff
id=$2 new=new_$diff
echo "My id is $1"
echo "I want to sync for user account $id"
##awk command I am using is as below
cat $diff | awk... (2 Replies)
Hi
i am studying about raid partion.i am not able to understand RAID level 5.
below is excerpt taken from tutorial.
RAID level 5
are they trying to say that the will be one extra disk which contain all the data. let says there are 4 disk. out of 4 , 3 disk are used for storing data and... (15 Replies)
Hi,
I am trying to set ulimit for soft stack unlimited, but this is not taking effect, after tracing the ulimit -a unlimited command, the below output was generated, which i am unable to comprehend. Could any one help me with this?
prcbap1-r10prod: truss -d ulimit -s unlimited
Tue Dec 30... (2 Replies)
Discussion started by: NasirAbbasi
2 Replies
LEARN ABOUT BSD
egrep
GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output. Grep patterns are limited regular expressions in the style of ex(1); it uses a compact nondeterministic
algorithm. Egrep patterns are full regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space.
Fgrep patterns are fixed strings; it is fast and compact. The following options are recognized.
-v All lines but those matching are printed.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its relative line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-i The case of letters is ignored in making comparisons -- that is, upper and lower case are considered identical. This applies to
grep and fgrep only.
-s Silent mode. Nothing is printed (except error messages). This is useful for checking the error status.
-w The expression is searched for as a word (as if surrounded by `<' and `>', see ex(1).) (grep only)
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
In all cases the file name is shown if there is more than one input file. Care should be taken when using the characters $ * [ ^ | ( ) and
in the expression as they are also meaningful to the Shell. It is safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character other than newline matches that character.
The character ^ matches the beginning of a line.
The character $ matches the end of a line.
A . (period) matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by an * (asterisk) matches a sequence of 0 or more matches of the regular expression. A regular
expression followed by a + (plus) matches a sequence of 1 or more matches of the regular expression. A regular expression followed
by a ? (question mark) matches a sequence of 0 or 1 matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
SEE ALSO ex(1), sed(1), sh(1)DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Lines are limited to 256 characters; longer lines are truncated.
4th Berkeley Distribution April 29, 1985 GREP(1)