Checking for null value Post: 302309113

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Null Value

Hello All, I have a file of the format **** 123 abc ABC 456 bcd BCD 789 def 112 ghi GHI 223 jkl 344 mno MNO **** I am trying to extract the lines that have no values in the third field (in this case, this would be 789 def 223 jkl Can anyone please help??...

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compare null with non-null

I've got a very peculiar situation. I'm trying to find out if we can compare null fields with non-null. I've output csv files from SQL and Oracle. I need to compare each field from the files, and then find out any differences. The files usualy have over 500 fields, and send the resule to DBA....

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void disptree(node *ptr) { if ((ptr->left) !=NULL) disptree(ptr->left); cout<<"Position:"<<ptr->pos<<" Data:"<<ptr->data<<endl; if ((ptr->right)!=NULL; disptree(ptr->right); } i'm getting a segmentation fault at the red line. i cannot understand what's the problem....

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Insert string 'NULL' where there is a null value

I have an input file having 7 fields delimited by , eg : 1,ABC,hg,1,2,34,3 2,hj,YU,2,3,4, 3,JU,kl,4,5,7, 4,JK,KJ,3,56,4,5 The seventh field here in some lines is empty, whereas the other lines there is a value. How do I insert string NULL at this location (7th loc) for these lines where...

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/dev/null 2>&1 Versus /dev/null 2>1

How are these two different? They both prevent output and error from being displayed. I don't see the use of the "&" echo "hello" > /dev/null 2>&1 echo "hello" > /dev/null 2>1

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Hello All, I have this question that how to check for an array for NULL? For eg. #include<iostream.h> using namespace std; int main() { char arr; if(arr == NULL) { cout<<"NULL"; } } Thanks a lott in advance!!!

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NULL checking

Hi I need to check the output of a string to null. For eg the output I get for $KIT is empty. So want to echo something when the output is empty. How can I do that? Thanks in advance

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Redirecting standard out to /dev/null goes to file "/dev/null" instead

I apologize if this question has been answered else where or is too elementary. I ran across a KSH script (long unimportant story) that does this: if ; then CAS_SRC_LOG="/var/log/cas_src.log 2>&1" else CAS_SRC_LOG="/dev/null 2>&1" fithen does this: /usr/bin/echo "heartbeat:...

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Stop boot system at "Checking protected password and checking subsystem databases"

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Checking for null condition in a UNIX variable

i have this code for i in `cat sql_output.txt` do -- some script commands done sql_output.txt has 1 column with employee_ids If the sql_output.txt is null then the do loop should not execute. How can i implement this. for i in `cat sql_output.txt` If i is null or empty then ...

LEARN ABOUT V7

join

JOIN(1) 						      General Commands Manual							   JOIN(1)

NAME

       join - relational database operator

SYNOPSIS

       join [ options ] file1 file2

DESCRIPTION

       Join  forms,  on the standard output, a join of the two relations specified by the lines of file1 and file2.  If file1 is `-', the standard
       input is used.

       File1 and file2 must be sorted in increasing ASCII collating sequence on the fields on which they are to be joined, normally the  first	in
       each line.

       There  is  one line in the output for each pair of lines in file1 and file2 that have identical join fields.  The output line normally con-
       sists of the common field, then the rest of the line from file1, then the rest of the line from file2.

       Fields are normally separated by blank, tab or newline.	In this case, multiple separators count as one, and leading  separators  are  dis-
       carded.

       These options are recognized:

       -an    In addition to the normal output, produce a line for each unpairable line in file n, where n is 1 or 2.

       -e s   Replace empty output fields by string s.

       -jn m  Join on the mth field of file n.	If n is missing, use the mth field in each file.

       -o list
	      Each  output line comprises the fields specifed in list, each element of which has the form n.m, where n is a file number and m is a
	      field number.

       -tc    Use character c as a separator (tab character).  Every appearance of c in a line is significant.

SEE ALSO

       sort(1), comm(1), awk(1)

BUGS

       With default field separation, the collating sequence is that of sort -b; with -t, the sequence is that of a plain sort.

       The conventions of join, sort, comm, uniq, look and awk(1) are wildly incongruous.

																	   JOIN(1)

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

Null Value

Discussion started by: Khoomfire

2. Shell Programming and Scripting

compare null with non-null

Discussion started by: nitin

3. Programming

C++ segmentation fault while checking for null pointer

Discussion started by: vijaymrt

4. Shell Programming and Scripting

Insert string 'NULL' where there is a null value

Discussion started by: zilch