Posting your /etc/passwd here wouldn't be a good idea.
Using several grep processes to read some fields from it is no good idea either. And assigning fields to enumerated variables can exceed the number of variables if you don't exactly know how many data lines you are going to read. Grepping for 5000 just along the line may not be specific enough; unwanted fields may fulfill this condition and give false hits.
Why don't you try sth like
Hi all,
I have a shell script which calls other shell scripts, depending on the input.
Within a.sh, I have a command which calls b.sh (ie. ksh b.sh)
Normally, we use the exit function to terminate a shell. However, if I choose to call exit from b.sh, I will return to the parent shell who... (4 Replies)
Hi All,
I am going through the semaphore concept and have a doubt regarding the same and hope to get a resolution here.
I have a file which has a number of records.
I want to write an application (in C) which will be able to do concurrent read/write on these records.
Of what I have... (8 Replies)
Hi all
This is my first thread here.i confused with the concept of thread.Can anyone tell me this concept in detail.my Quation may be at primary level.
Thanx in advance for help. (1 Reply)
I have the following script running with nohup on one of my servers:
#!/bin/bash
#\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
#set log number
#i=1
#\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
#Check if log exits, if so incrememnt log number up so we don't clobber
#while... (8 Replies)
Hi all,
This is the basic question.
I have read many books which advised to avoid creating sub shells.
e.g: use wc -l<filename
rather than using cat file|wc -l.
So, how to identify whether a command creates subshell or not?
so,is it better to use tail -n+1 file in stead of using cat.... (3 Replies)
Hi Gurus,
Please help me in below requirement.
Instance =5 (it is user parameter)
total=52 (it is user parameter
i need to split this to 5 and reminder as 1 instances totally 6
for example i need to splitt to each
52/5=10.4
1-10
11-20
21-30
31-40
41-50 (2 Replies)
Hi there,
Everyone knows that errexit is NOT inherited by subshells. But does anyone know why errexit still appears as set with set +o?
The following example highlights the fact that errexit appears set in a subshell (set +o) even though it's actually unset (it does NOT exit with false).
$... (0 Replies)
So i have a script that is like this:
#!/bin/sh
VARA="elementary 1
elementary 2
nursery A
nursery B
highschool AZ"
echo "${ContentOfADifferentSCRIPT}" | sh
i do not have control over the script that is inside the variable "${ContentOfADifferentSCRIPT}".
however, i know that the... (3 Replies)
Discussion started by: SkySmart
3 Replies
LEARN ABOUT HPUX
read
read(1) General Commands Manual read(1)NAME
read - read a line from standard input
SYNOPSIS
var ...
DESCRIPTION
reads a single line from standard input. The line is split into fields as when processed by the shell (refer to shells in the first field
is assigned to the first variable var, the second field to the second variable var, and so forth. If there are more fields than there are
specified var operands, the remaining fields and their intervening separators are assigned to the last var. If there are more vars than
fields, the remaining vars are set to empty strings.
The setting of variables specified by the var operands affect the current shell execution environment.
Standard input to can be redirected from a text file.
Since affects the current shell execution environment, it is usually provided as a normal shell special (built-in) command. Thus, if it is
called in a subshell or separate utility execution environment similar to the following, it does not affect the shell variables in the
caller's environment:
Options
recognizes the following options:
Do not treat a backslash character in any special way.
Consider each backslash to be part of the input line.
Opperands
recognizes the following operands:
var The name of an existing or nonexisting shell variable.
EXTERNAL INFLUENCES
Environment Variables
determines the internal field separators used to delimit fields.
RETURN VALUE
exits with one of the following values:
0 Successful completion.
>0 End-of-file was detected or an error occurred.
EXAMPLES
Print a file with the first field of each line moved to the end of the line.
while read -r xx yy
do
printf "%s %s
" "$yy" "$xx"
done < input_file
SEE ALSO csh(1), ksh(1), sh(1), sh-posix(1).
STANDARDS CONFORMANCE read(1)