Sponsored Content
Full Discussion: Checking for null value
Top Forums Shell Programming and Scripting Checking for null value Post 302309116 by ganapathi.t on Tuesday 21st of April 2009 06:38:03 AM
Old 04-21-2009
It is working fine, if I have only one space. But in my input file, I might have more than single space say " " or " " or " " etc. But I dont know the exact number of spaces.
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

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??... (1 Reply)
Discussion started by: Khoomfire
1 Replies

2. Shell Programming and Scripting

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.... (8 Replies)
Discussion started by: nitin
8 Replies

3. Programming

C++ segmentation fault while checking for null pointer

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.... (3 Replies)
Discussion started by: vijaymrt
3 Replies

4. Shell Programming and Scripting

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... (8 Replies)
Discussion started by: zilch
8 Replies

5. UNIX for Dummies Questions & Answers

/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 (3 Replies)
Discussion started by: glev2005
3 Replies

6. Programming

Checking an array for NULL in C++

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!!! (3 Replies)
Discussion started by: mind@work
3 Replies

7. Shell Programming and Scripting

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 (6 Replies)
Discussion started by: Ananthdoss
6 Replies

8. Shell Programming and Scripting

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:... (5 Replies)
Discussion started by: jbmorrisonjr
5 Replies

9. SCO

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

Hi, (i'm sorry for my english) I'm a problem on boot sco unix 5.0.5 open server. this stop at "Checking protected password and checking subsystem databases" (See this image ) I'm try this: 1) http://www.digipedia.pl/usenet/thread/50/37093/#post37094 2) SCO: SCO Unix - Server hangs... (9 Replies)
Discussion started by: buji
9 Replies

10. Shell Programming and Scripting

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 ... (5 Replies)
Discussion started by: rafa_fed2
5 Replies
FMT(1)							    BSD General Commands Manual 						    FMT(1)

NAME
fmt -- simple text formatter SYNOPSIS
fmt [-cmnps] [-d chars] [-l num] [-t num] [goal [maximum] | -width | -w width] [file ...] DESCRIPTION
The fmt utility is a simple text formatter which reads the concatenation of input files (or standard input if none are given) and produces on standard output a version of its input with lines as close to the goal length as possible without exceeding the maximum. The goal length defaults to 65 and the maximum to 10 more than the goal length. Alternatively, a single width parameter can be specified either by prepend- ing a hyphen to it or by using -w. For example, ``fmt -w 72'', ``fmt -72'', and ``fmt 72 72'' all produce identical output. The spacing at the beginning of the input lines is preserved in the output, as are blank lines and interword spacing. Lines are joined or split only at white space; that is, words are never joined or hyphenated. The options are as follows: -c Center the text, line by line. In this case, most of the other options are ignored; no splitting or joining of lines is done. -m Try to format mail header lines contained in the input sensibly. -n Format lines beginning with a '.' (dot) character. Normally, fmt does not fill these lines, for compatibility with nroff(1). -p Allow indented paragraphs. Without the -p flag, any change in the amount of whitespace at the start of a line results in a new para- graph being begun. -s Collapse whitespace inside lines, so that multiple whitespace characters are turned into a single space. (Or, at the end of a sen- tence, a double space.) -d chars Treat the chars (and no others) as sentence-ending characters. By default the sentence-ending characters are full stop ('.'), ques- tion mark ('?') and exclamation mark ('!'). Remember that some characters may need to be escaped to protect them from your shell. -l number Replace multiple spaces with tabs at the start of each output line, if possible. Each number spaces will be replaced with one tab. The default is 8. If number is 0, spaces are preserved. -t number Assume that the input files' tabs assume number spaces per tab stop. The default is 8. The fmt utility is meant to format mail messages prior to sending, but may also be useful for other simple tasks. For instance, within vis- ual mode of the ex(1) editor (e.g., vi(1)) the command !}fmt will reformat a paragraph, evening the lines. ENVIRONMENT
The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of fmt as described in environ(7). SEE ALSO
fold(1), mail(1), nroff(1) HISTORY
The fmt command appeared in 3BSD. The version described herein is a complete rewrite and appeared in FreeBSD 4.4. AUTHORS
Kurt Shoens Liz Allen (added goal length concept) Gareth McCaughan BUGS
The program was designed to be simple and fast - for more complex operations, the standard text processors are likely to be more appropriate. When the first line of an indented paragraph is very long (more than about twice the goal length), the indentation in the output can be wrong. The fmt utility is not infallible in guessing what lines are mail headers and what lines are not. BSD
August 2, 2004 BSD
All times are GMT -4. The time now is 05:31 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy