10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi,
I am trying to write a shell script to help with some digital signature work currently being undertaken where we have a file that contains a number of rows ending with ^M.
What I need to do is concatenate this using shell scripting and retain the control character. E.G.
abc^M... (5 Replies)
Discussion started by: chris01010
5 Replies
2. Shell Programming and Scripting
I want to read a file -line by line which consists of the following statements
Chr18:4000-4010
Chr20:4020-4030
Chr15:8000-8050
Pls. give a expression to read the line like this from a file
Chr18:4000-4010
the given two replies reading like that
Chr18:-10
but it is important to... (2 Replies)
Discussion started by: hravisankar
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3. UNIX and Linux Applications
In LVM I have one volume grp and it has two logical volumes A and B and both are full,so I extended my volume grp to 1GB with another hard disk and add this space to A and put my resr data .Now problem is that I get data from first hard disk only but I m unable to find data which is in second hard... (0 Replies)
Discussion started by: Rahul chauhan
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4. Shell Programming and Scripting
How do I filter only comments and still keep Line breaks at the end of the line!?
This is one of the common tasks we all do,, How can we do this in a right way..!?
I try to ignore empty lines and commented lines using following approach.
test.sh
# \040 --> SPACE character octal... (17 Replies)
Discussion started by: kchinnam
17 Replies
5. Shell Programming and Scripting
Hi Guys,
I am having a file which does not have any name when i do a ls -l
-rw-r--r-- 1 dctrdat1 dctrdata 35 Feb 09 08:04
-rw-r--r-- 1 dctrdat1 dctrdata 11961 Feb 08 06:40 DAI_data.txt
Now i want to see what is inside that file. Can you please let me know how to read... (9 Replies)
Discussion started by: mac4rfree
9 Replies
6. Shell Programming and Scripting
Can anyone tell me how to read a file in perl having junk characters . I have only one junk character which is repeated many times in the file. While i'm reading and printing the file , it is displaying till the 1st occurence of that junk character and rest of the file is not being read. (1 Reply)
Discussion started by: k_surya
1 Replies
7. Shell Programming and Scripting
i need to read record by record i use script
#!/bin/ksh
for i in 'cat filename'
do
echo $1
done
but i dont get expected result
i just get filename echoed on screen (4 Replies)
Discussion started by: er_zeeshan05
4 Replies
8. UNIX for Advanced & Expert Users
I am not able to receive the message on socket in the current process when its waiting for its child to exit.
code looks something like below
//in one thread of the current process
//thread 1
===============================================
int numBytes = read(sockid,buf,SIZE); //Now the... (2 Replies)
Discussion started by: swap007
2 Replies
9. Programming
We have to convert a sequential file to a 80 char line sequential file (HP UX platform).The sequential file contains special characters. which after conversion of the file to line sequential are getting coverted into "new line" or "tab" and file is getting distorted. Is there any way to read these... (2 Replies)
Discussion started by: Rajeshsu
2 Replies
10. Shell Programming and Scripting
Hello,
I am new to shell scripting, and I am trying to create a script that reads an input like the following
firstname:lastname:age
firstname:lastname:age
firstname:lastname:age
in a text file. I have a 2 part question. First how do I open the file in a shell script. And then how can... (7 Replies)
Discussion started by: TexasGuy
7 Replies
read(1) User Commands read(1)
NAME
read - read a line from standard input
SYNOPSIS
/usr/bin/read [-r] var...
sh
read name...
csh
set variable = $<
ksh
read [ -prsu [n]] [ name ? prompt] [name...]
DESCRIPTION
/usr/bin/read
The read utility will read a single line from standard input.
By default, unless the -r option is specified, backslash () acts as an escape character. If standard input is a terminal device and the
invoking shell is interactive, read will prompt for a continuation line when:
o The shell reads an input line ending with a backslash, unless the -r option is specified.
o A here-document is not terminated after a NEWLINE character is entered.
The line will be split into fields as in the shell. The first field will be assigned to the first variable var, the second field to the
second variable var, and so forth. If there are fewer var operands specified than there are fields, the leftover fields and their interven-
ing separators will be assigned to the last var. If there are fewer fields than vars, the remaining vars will be set to empty strings.
The setting of variables specified by the var operands will affect the current shell execution environment. If it is called in a subshell
or separate utility execution environment, such as one of the following:
(read foo)
nohup read ...
find . -exec read ... ;
it will not affect the shell variables in the caller's environment.
The standard input must be a text file.
sh
One line is read from the standard input and, using the internal field separator, IFS (normally space or tab), to delimit word boundaries,
the first word is assigned to the first name, the second word to the second name, and so on, with leftover words assigned to the last name.
Lines can be continued using
ewline. Characters other than NEWLINE can be quoted by preceding them with a backslash. These backslashes
are removed before words are assigned to names, and no interpretation is done on the character that follows the backslash. The return code
is 0, unless an end-of-file is encountered.
csh
The notation:
set variable = $<
loads one line of standard input as the value for variable. (See csh(1)).
ksh
The shell input mechanism. One line is read and is broken up into fields using the characters in IFS as separators. The escape character,
(), is used to remove any special meaning for the next character and for line continuation. In raw mode, -r, the character is not
treated specially. The first field is assigned to the first name, the second field to the second name, and so on, with leftover fields
assigned to the last name. The -p option causes the input line to be taken from the input pipe of a process spawned by the shell using |&.
If the -s flag is present, the input will be saved as a command in the history file. The flag -u can be used to specify a one digit file
descriptor unit n to read from. The file descriptor can be opened with the exec special command. The default value of n is 0. If name is
omitted, REPLY is used as the default name. The exit status is 0 unless the input file is not open for reading or an end-of-file is encoun-
tered. An end-of-file with the -p option causes cleanup for this process so that another can be spawned. If the first argument contains a
?, the remainder of this word is used as a prompt on standard error when the shell is interactive. The exit status is 0 unless an end-of-
file is encountered.
OPTIONS
The following option is supported:
-r Does not treat a backslash character in any special way. Considers each backslash to be part of the input line.
OPERANDS
The following operand is supported:
var The name of an existing or non-existing shell variable.
EXAMPLES
Example 1: An example of the read command
The following example for /usr/bin/read prints a file with the first field of each line moved to the end of the line:
example% while read -r xx yy
do
printf "%s %s
" "$yy" "$xx"
done < input_file
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of read: LANG, LC_ALL, LC_CTYPE, LC_MES-
SAGES, and NLSPATH.
IFS Determines the internal field separators used to delimit fields.
PS2 Provides the prompt string that an interactive shell will write to standard error when a line ending with a backslash is read and
the -r option was not specified, or if a here-document is not terminated after a newline character is entered.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
>0 End-of-file was detected or an error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
SEE ALSO
csh(1), ksh(1), line(1), set(1), sh(1), attributes(5), environ(5), standards(5)
SunOS 5.10 28 Mar 1995 read(1)