Please become accustomed to provide decent context info of your problem.
It is always helpful to support a request with system info like OS and shell, related environment (variables, options), preferred tools, adequate (representative) sample input and desired output data and the logics connecting the two, and, if existent, system (error) messages verbatim, to avoid ambiguities and keep people from guessing.
Should your desire be to solve above in shell, and yours is bourne compatible, there are many threads dealing with and presenting solutions to your problem. A very simplified approach would be to use redirection from extra file descriptors:
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)
To make it clearer:
I have a file, List.txt
List.txt contains: (these are actually splitted files w/c I got from ls command and dump them to the List.txt file)
SAMPLEa
SAMPLEb
SAMPLEc
SAMPLEd
SAMPLEe
SAMPLEf
.
.
.
.
.
And I want to rename these files to have a .dat extension.... (3 Replies)
I am writing a shell script using the korn shell. It seems that I am only
able to use local variables within a while loop that is reading a file.
(I can't access a variable outside a previously used while loop.) It's been
a while since I wrote shell scripts. Here is a sample
cat file.txt... (4 Replies)
Hi,
I am building a script to grep for a string in all the files from a folder and display the results.
I am reading the files one by one by placing the names in other file using while loop
my code is as below
while read inp
do
chk=`grep -c "$str" $pth/$inp`
... (2 Replies)
Hi.
I have a process that execute a Microfocus Cobol. This process read a large sequential file and update or insert in a table Oracle.
This process run smoothly in some ocasions but in a file whor have more than 400,000 registers, the cobol program doesn't finish read all the records,... (3 Replies)
Writing a Tool to simulate non-sequential disk I/O (simulate db file sequential read) in C POSIX
I have over the years come across the same issue a couple of times, and it normally is that the read speed on SAN is absolutely atrocious when doing non-sequential I/O to the disks. Problem being of... (7 Replies)
Hi,
I am on HP-UX and K shell.
When I am using while/for loop for reading a file. It is working fine but not reading tabs:
Suppose, if the line is: ; ;COMP; ; ; ;
then loop is reading as
; ;COMP; ;... (5 Replies)
Hi All,
I need small help on for loop syntax in C shell.
How can we read the values from a file (line by line) through C shell loop.
For Ex:
$Cat file1
data1
data2
data3
data4
$
I have to print those values in a variable and have to perform some steps...
Can anyone help on... (2 Replies)
Hi,
I am writing in a file through cat command. This file will contain the path of file along with filename. e.g. /home/user/folder1/folder2/filename.txt
There might be very large number of this path in same file like say 140
when I try to run while command:
while read -r file
do
//command... (8 Replies)
Discussion started by: Pulkit Lall
8 Replies
LEARN ABOUT MINIX
exec
exec(1) User Commands exec(1)NAME
exec, eval, source - shell built-in functions to execute other commands
SYNOPSIS
sh
exec [argument...]
eval [argument...]
csh
exec command
eval argument...
source [-h] name
ksh
*exec [arg...]
*eval [arg...]
DESCRIPTION
sh
The exec command specified by the arguments is executed in place of this shell without creating a new process. Input/output arguments may
appear and, if no other arguments are given, cause the shell input/output to be modified.
The arguments to the eval built-in are read as input to the shell and the resulting command(s) executed.
csh
exec executes command in place of the current shell, which terminates.
eval reads its arguments as input to the shell and executes the resulting command(s). This is usually used to execute commands generated as
the result of command or variable substitution.
source reads commands from name. source commands may be nested, but if they are nested too deeply the shell may run out of file descrip-
tors. An error in a sourced file at any level terminates all nested source commands.
-h Place commands from the file name on the history list without executing them.
ksh
With the exec built-in, if arg is given, the command specified by the arguments is executed in place of this shell without creating a new
process. Input/output arguments may appear and affect the current process. If no arguments are given the effect of this command is to mod-
ify file descriptors as prescribed by the input/output redirection list. In this case, any file descriptor numbers greater than 2 that are
opened with this mechanism are closed when invoking another program.
The arguments to eval are read as input to the shell and the resulting command(s) executed.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
EXIT STATUS
For ksh:
If command is not found, the exit status is 127. If command is found, but is not an executable utility, the exit status is 126. If a redi-
rection error occurs, the shell exits with a value in the range 1-125. Otherwise, exec returns a zero exit status.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), ksh(1), sh(1), attributes(5)SunOS 5.10 17 Jul 2002 exec(1)