As far as I have understood the task is more a merge:
for each file you need to read one line from the number file. Nested loops are not appropriate (and leads to inefficiency).
With shell-builtins
The file3 is opened with an extra descriptor 3 where the read reads one line from (could have been just the < and simple read here, but is safer in case some more code would read from stdin).
Like the for-done block gets an opened input file, there is an artificial { block } that gets an opened destination file as stdout.
Last edited by MadeInGermany; 08-18-2016 at 08:56 AM..
Hi,
Actually I have a file which consists data . for eg names.
Then I want my sql query to read this file and produce the output.
Currently I am using this
FOR EG : FILENAME is NAMES
for i in `cat NAMES`
{
sqlplus -s $CONNECTID << EOF
spool rooh
set heading off
select... (1 Reply)
I am pretty new to this, but imagine what I am trying to do is possible
iI am trying to make an automated DB comparison tool that selects all columns in all tables and compares them to the same thing in another DB.
anyway I have created 2 files to help with this
the first file is a... (13 Replies)
Hi
I have around 100 users in sun server and have default home directory in /usr/home/<username>
I want to clean their home directory time to time to make free space on root, as users generate many output files during usage of application.
My idea is, generate a file with following command... (4 Replies)
Hi guys
I having som problem trying to use sed to get a file and insert inside another one. I'll try to explain better.
I have a base.txt and using sed(having a array variables) I'm chaging some strings inside this file and saving as base1.txt. until here okay.
Then, I have to get this... (4 Replies)
I run into a issue when I try to do sorting of the following with ascending order, one round of for looping seems not working, anyone knows how to use shell or perl?
$array = (5,0,3,2,7,9,8) (2 Replies)
Hello, where can I get usefull information on the use of looping with for , if and while with extensive examples.
Also use of variables in scripts (1 Reply)
Hi,
Now I have written a script which sorts the records in the file and splits them according to some condition.
Now, I need to modify the script so that it reads all the files one after the other and does the sorting & splitting.
Pls help me in reading all the files in a directory and... (8 Replies)
Although my sed skills are gradually developing, thanks in large part to this forum, I'm having a hard time dealing with pattern space and looping, which I suspect is what I'll need a better handle on to figure out my current issue, which is converting a multi line file like this:
... (4 Replies)
Hey guys, so I am trying to do a loop script that will go through each folder (no gui so just each domain has a folder) and grab out the databases being used on that domain. I know I would use
mysql -e "show databases where not 'information_schema';" once in each directory to pull the actual... (3 Replies)
Discussion started by: dough
3 Replies
LEARN ABOUT SUSE
read
read(n) Tcl Built-In Commands read(n)
__________________________________________________________________________________________________________________________________________________NAME
read - Read from a channel
SYNOPSIS
read ?-nonewline? channelId
read channelId numChars
_________________________________________________________________DESCRIPTION
In the first form, the read command reads all of the data from channelId up to the end of the file. If the -nonewline switch is specified
then the last character of the file is discarded if it is a newline. In the second form, the extra argument specifies how many characters
to read. Exactly that many characters will be read and returned, unless there are fewer than numChars left in the file; in this case all
the remaining characters are returned. If the channel is configured to use a multi-byte encoding, then the number of characters read may
not be the same as the number of bytes read.
ChannelId must be an identifier for an open channel such as the Tcl standard input channel (stdin), the return value from an invocation of
open or socket, or the result of a channel creation command provided by a Tcl extension. The channel must have been opened for input.
If channelId is in nonblocking mode, the command may not read as many characters as requested: once all available input has been read, the
command will return the data that is available rather than blocking for more input. If the channel is configured to use a multi-byte
encoding, then there may actually be some bytes remaining in the internal buffers that do not form a complete character. These bytes will
not be returned until a complete character is available or end-of-file is reached. The -nonewline switch is ignored if the command returns
before reaching the end of the file.
Read translates end-of-line sequences in the input into newline characters according to the -translation option for the channel. See the
fconfigure manual entry for a discussion on ways in which fconfigure will alter input.
USE WITH SERIAL PORTS
For most applications a channel connected to a serial port should be configured to be nonblocking: fconfigure channelId -blocking 0. Then
read behaves much like described above. Care must be taken when using read on blocking serial ports:
read channelId numChars
In this form read blocks until numChars have been received from the serial port.
read channelId
In this form read blocks until the reception of the end-of-file character, see fconfigure -eofchar. If there no end-of-file charac-
ter has been configured for the channel, then read will block forever.
EXAMPLE
This example code reads a file all at once, and splits it into a list, with each line in the file corresponding to an element in the list:
set fl [open /proc/meminfo]
set data [read $fl]
close $fl
set lines [split $data
]
SEE ALSO
file(n), eof(n), fblocked(n), fconfigure(n), Tcl_StandardChannels(3)KEYWORDS
blocking, channel, end of line, end of file, nonblocking, read, translation, encoding
Tcl 8.1 read(n)