hey guys, how do i replace only a line within a file without messing up the rest of the contents of the file?
see, if possible can you guys give me a straight forward way to do this. i dont want a complex command. what i mean is i know i can accomplish this by using sed, well, i think i can,... (3 Replies)
I have a problem in the following code ...
while read line
do
#Get Line Number
OLDLINE=`sed -n $Lineno $filename`
echo "Un Changed Line : "$OLDLINE
echo "Enter a New Pattern : "
read NewPattern <&1
echo "NewPattern :"$NewPattern
NEWLINE=`cat $filename | sed -n... (1 Reply)
STEP 1
# Set variable
FILE=/tmp/mainfile
SEARCHFILE =/tmp/searchfile
# THIS IS THE MAIN FILE.
cat /tmp/mainfile
Interface Ethernet0/0 "outside", is up, line protocol is up
Hardware is i82546GB rev03, BW 100 Mbps
Full-Duplex(Full-duplex), 100 Mbps(100 Mbps)
MAC address... (6 Replies)
Hello,
I have two files that I need to compare and print out the line from file2 that has the first 6 fields matching the first 6 fields in file1. Complicating this are the following restrictions
1. file1 is only a few thousand lines at most and file2 is greater than 2 million
2. I need to... (7 Replies)
File 1
<html>ta da....unique file name I want to give file=>343...</html>
<html>da ta 234 </html>
<html>pa da 542 </html>
and so on...
File 2
343
234
542
and so on, each line in File 1 one also corresponds with each line in File 2
I have tried several grep, sed, while .. read, do,... (4 Replies)
Hi All,
I have a set of files named S5_SK1.chr01 S5_SK1.chr02 S5_SK1.chr03 ..... and the first line of these files is >SK1.chr01 >SK1.chr02 >SK1.chr03 ..... Can anyone suggest how I can change the first line of all these files with the filename itself? So my expected output for the first lines of... (14 Replies)
I have a file which has a list in it
pop
triangle
people
slow
fast
What I want to do is search this list and replace people with humans do the list looks like this:
pop
triangle
human
slow
fast
I think i use something like this....
if cat /list.txt | grep -q 'people' ; then (9 Replies)
Hi all,
I need to replace a line
export TZ=xxxxxxxx
with the line
export TZ=$1
Now, "xxxxxxxx" in the above line is some unknown string and $1 is a parameter. I want the content of $1 to be replaced with "xxxxxxxx".
Kindly help me how to do this in the shell scripting. (5 Replies)
Good day,
I have a list of regular expressions in file1. For each match in file2, print the containing line and the line after.
file1:
file2:
Output:
I can match a regex and print the line and line after
awk '{lines = $0} /Macrosiphum_rosae/ {print lines ; print lines } '
... (1 Reply)
Dear friends,
I have two files. One with all IDs(in a single field) . And another with data(of which say field 5 is ID). I want to create an array of IDs using first file and
while reading second file if the ID appears in the array I need to print $0 else skip.
After a long gap I am... (6 Replies)
Discussion started by: paresh n doshi
6 Replies
LEARN ABOUT OPENDARWIN
mktemp
MKTEMP(1) BSD General Commands Manual MKTEMP(1)NAME
mktemp -- make temporary file name (unique)
SYNOPSIS
mktemp [-d] [-q] [-t prefix] [-u] template ...
mktemp [-d] [-q] [-u] -t prefix
DESCRIPTION
The mktemp utility takes each of the given file name templates and overwrites a portion of it to create a file name. This file name is
unique and suitable for use by the application. The template may be any file name with some number of 'Xs' appended to it, for example
/tmp/temp.XXXX. The trailing 'Xs' are replaced with the current process number and/or a unique letter combination. The number of unique
file names mktemp can return depends on the number of 'Xs' provided; six 'Xs' will result in mktemp testing roughly 26 ** 6 combinations.
If mktemp can successfully generate a unique file name, the file is created with mode 0600 (unless the -u flag is given) and the filename is
printed to standard output.
If the -t prefix option is given, mktemp will generate an template string based on the prefix and the TMPDIR environment variable if set.
The default location if TMPDIR is not set is /tmp. Care should be taken to ensure that it is appropriate to use an environment variable
potentially supplied by the user.
Any number of temporary files may be created in a single invocation, including one based on the internal template resulting from the -t flag.
Mktemp is provided to allow shell scripts to safely use temporary files. Traditionally, many shell scripts take the name of the program with
the pid as a suffix and use that as a temporary file name. This kind of naming scheme is predictable and the race condition it creates is
easy for an attacker to win. A safer, though still inferior, approach is to make a temporary directory using the same naming scheme. While
this does allow one to guarantee that a temporary file will not be subverted, it still allows a simple denial of service attack. For these
reasons it is suggested that mktemp be used instead.
OPTIONS
The available options are as follows:
-d Make a directory instead of a file.
-q Fail silently if an error occurs. This is useful if a script does not want error output to go to standard error.
-t prefix
Generate a template (using the supplied prefix and TMPDIR if set) to create a filename template.
-u Operate in ``unsafe'' mode. The temp file will be unlinked before mktemp exits. This is slightly better than mktemp(3) but still
introduces a race condition. Use of this option is not encouraged.
DIAGNOSTICS
The mktemp utility exits 0 on success, and 1 if an error occurs.
EXAMPLES
The following sh(1) fragment illustrates a simple use of mktemp where the script should quit if it cannot get a safe temporary file.
tempfoo=`basename $0`
TMPFILE=`mktemp /tmp/${tempfoo}.XXXXXX` || exit 1
echo "program output" >> $TMPFILE
To allow the use of $TMPDIR:
tempfoo=`basename $0`
TMPFILE=`mktemp -t ${tempfoo}` || exit 1
echo "program output" >> $TMPFILE
In this case, we want the script to catch the error itself.
tempfoo=`basename $0`
TMPFILE=`mktemp -q /tmp/${tempfoo}.XXXXXX`
if [ $? -ne 0 ]; then
echo "$0: Can't create temp file, exiting..."
exit 1
fi
SEE ALSO mkdtemp(3), mkstemp(3), mktemp(3), environ(7)HISTORY
A mktemp utility appeared in OpenBSD 2.1. This implementation was written independently based on the OpenBSD man page, and first appeared in
FreeBSD 2.2.7. This man page is taken from OpenBSD
BSD November 20, 1996 BSD