We use a UNIX-based system (Lawson) at work and I was given this command to request a data extract from the db admin. The only thing I really understand is the last line as it appears to be joining the files created from the first three lines into one. Is there anyone who can help me breakdown the... (4 Replies)
# 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)
i am analyzing a query written by another developer ,need to understand part of script
am looking at a code ..and it converts comma files to pipe delimited and also takes away quotes from any columns,
source field format: 2510,"Debbie",NewYork
changes to
target: 2510|Debbie|NewYork
... (1 Reply)
Can someone explain what is happening line by line in this script, particularly after the do statement. The script works, it renames all the files in my directory that has a date in the file name. But I would like to know more about it.
#!/bin/bash
newdate=12-10-1995
for file in *--*
do
... (6 Replies)
i am trying to understand this script example. the text does not explain it. can someone tell me briefly what each of the functions do. any help will be appreciated.
#!/bin/bash
killtree() {
local _pid=$1
local _sig=${2-TERM}
for _child in $(ps -o pid --no-headers --ppid... (1 Reply)
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 $?`
while
I do not... (3 Replies)
Hi,
New to this forum, as well as to unix scripting..need help to understand below script ...
sendNotice_sp()
{
ATTACH=${LNXLOG:-}
if ; then
if ; then
mail -s "$ERR_MSG" $ERR_EMAIL_TO < $ATTACH
fi
else
mail -s "$ERR_MSG" $ERR_EMAIL_TO < /dev/null
fi
}
afaik this is sm kind of... (6 Replies)
Could someone please help me in understanding the code below:
#!/usr/bin/ksh
Month=`date|cut -c5-7`
Day=`date|cut -c9-10`
Year=`date|cut -c27-28`
Rom2Jul() { case $Month in Feb) Day=$(( $Day+31 ));;
Mar) Day=$((... (27 Replies)
Below script is called as Reducer, I am not sure how it work, can some expert explain me what this script does as i am a beginner.
inputfile:
hi hi how are are you
code:
#!/bin/bash
lastkey=""; -- what does this mean, because i saw in debug mode it is taking value as hi
count=0;... (13 Replies)
Hello,
How come the following script adds each numeric value to a total sum ?
x=$1
func()
{
for i in $1 $2 $3; do
let x= $x+$i
done }
func "8 8 8" 9 9
echo $x
A.How the program sums the string "8 8 8" if it`s only the first field value ($1)?
B.If we define x to be $1... (3 Replies)
Discussion started by: uniran
3 Replies
LEARN ABOUT OPENDARWIN
expr
EXPR(1) BSD General Commands Manual EXPR(1)NAME
expr -- evaluate expression
SYNOPSIS
expr expression
DESCRIPTION
The expr utility evaluates expression and writes the result on standard output.
All operators are separate arguments to the expr utility. Characters special to the command interpreter must be escaped.
Operators are listed below in order of increasing precedence. Operators with equal precedence are grouped within { } symbols.
expr1 | expr2
Returns the evaluation of expr1 if it is neither an empty string nor zero; otherwise, returns the evaluation of expr2.
expr1 & expr2
Returns the evaluation of expr1 if neither expression evaluates to an empty string or zero; otherwise, returns zero.
expr1 {=, >, >=, <, <=, !=} expr2
Returns the results of integer comparison if both arguments are integers; otherwise, returns the results of string comparison using
the locale-specific collation sequence. The result of each comparison is 1 if the specified relation is true, or 0 if the relation
is false.
expr1 {+, -} expr2
Returns the results of addition or subtraction of integer-valued arguments.
expr1 {*, /, %} expr2
Returns the results of multiplication, integer division, or remainder of integer-valued arguments.
expr1 : expr2
The ``:'' operator matches expr1 against expr2, which must be a regular expression. The regular expression is anchored to the begin-
ning of the string with an implicit ``^''. expr expects "basic" regular expressions, see re_format(7) for more information on regu-
lar expressions.
If the match succeeds and the pattern contains at least one regular expression subexpression ``(...)'', the string corresponding to
``1'' is returned; otherwise the matching operator returns the number of characters matched. If the match fails and the pattern
contains a regular expression subexpression the null string is returned; otherwise 0.
Parentheses are used for grouping in the usual manner.
EXAMPLES
1. The following example adds one to the variable a.
a=`expr $a + 1`
2. The following example returns the filename portion of a pathname stored in variable a. The // characters act to eliminate ambiguity
with the division operator.
expr //$a : '.*/(.*)'
3. The following example returns the number of characters in variable a.
expr $a : '.*'
DIAGNOSTICS
The expr utility exits with one of the following values:
0 the expression is neither an empty string nor 0.
1 the expression is an empty string or 0.
2 the expression is invalid.
STANDARDS
The expr utility conforms to IEEE Std 1003.2 (``POSIX.2'').
BSD July 3, 1993 BSD