Am a beginner in unix and I have just landed into a snag. The bash app I am working on is very simple and is one that can add contacts, and remove contacts (based on first and last name). Below is a part of my code, and for some reason, the grep displays the remaining contacts fine when excluding the (>contacts_file), but doesn't save to the file when including (>contacts_file). It instead leaves the 'contacts_file' blank. How can I fix this? Or is there a better way to search contacts in a contact's file? format in contacts_file is: firstname lastname
echo "[Remove a contact]"
echo "First Name: "
read first0
echo "Last Name: "
read last0
grep -vw -e "$first0 $last0" contacts_file >contacts_file
You cannot direct output to the same file in which you are grepping.
The reason is that the shell opens that output file for writing and hence makes it empty.
The solution is to direct output to a temp file and then move the temp file to contacts_file if you want to replace it.
Related
I have a folder named datafolder which contains five csv files aa.csv ab.csv ac.csv ad.csv ae.csv Each csv file contains data from an excel sheet in the format: date, product type, name, address etc. and I am only interested in the second column which is named product. Basically what I want to happen is for the jobmaster script to count the number of files in datafolder and then to start a map process for each individual file. I have the following scripts:
The jobmaster script runs without problems, however once the map script starts, only the first echo mapping $1 is displaying and the process is stuck in an infinite loop (my guess). When I run the ps command I expect to see 5 map.sh running, however there are none.
I suspect you missed an input redirection in map.sh:
file=$1
echo "mapping $file"
while IFS="," read -r value1 product remainder; do
# ...
done < "$file"
# ^^^^^ provide the standard input to from this file to `read`
I have a file, in AIX server, with multiple record entries in below format
Name(ABC XYZ) Gender(Male)
AGE(26) BDay(1990-12-09)
My problem is I want to extract the name and the b'day from the file for all the records. I am trying to list it like below:
ABC XYZ 1990-12-09
Can someone please help me with the scripting
Something like this maybe:
awk -F"[()]" '/Name/ && /Gender/{name=$2} /BDay/{print name,$4}' file.txt
That says... "treat opening and closing parentheses as field separators. If you see a line go by that contains Name and Gender, save the second field in the variable name. If you see a line go by that contains the word Bday, print out the last name you saw and also the fourth field on the current line."
I am trying to redirect emails that match a particular pattern to a shell script which will create files containing the texts, with datestamped filenames.
First, here is the routine from .procmailrc that hands the emails off to the script:
:0c:
* Subject: ^Ingest_q.*
| /home/myname/procmail/process
and here is the script 'process':
#!/bin/bash
DATE=`date +%F_%N`
FILE=/home/myname/procmail/${DATE}_email.txt
while read line
do
echo "$line" 1>>"$FILE";
done
I have gotten very frustrated with this because I can pipe text to this script on the command line and it works fine:
mybox-248: echo 'foo' | process
mybox-249: ls
2013-07-31_856743000_email.txt process
The file contains the word 'foo.'
I have been trying to get an email text to get output as a date-stamped file for hours now, and nothing has worked.
(I've also turned logging on in my .procmailrc and that isn't working either -- I'm not trying to ask a second question by mentioning that, just wondering if that might provide some hint as to what I might be doing wrong ...).
Thanks,
GB
Quoting your attempt:
:0c:
* Subject: ^Ingest_q.*
| /home/myname/procmail/process
The regex is wrong, ^ only matches at beginning of line, so it cannot occur after Subject:. Try this instead.
:0c:process.lock
* ^Subject: Ingest_q
| /home/myname/procmail/process
I also specified a named lockfile; I do not believe Procmail can infer a lock file name from just a script name. As you might have multiple email messages being delivered at the same time, and you don't want their logging intermingled in the log file, using a lock file is required here.
Finally, the trailing .* in the regex is completely redundant, so I removed it.
(The olde Procmail mini-FAQ also addresses both of these issues.)
I realize your recipe is probably just a quick test before you start on something bigger, but the entire recipe invoking the process script can be completely replaced by something like
MAILDIR=/home/myname/procmail
DATE=`date +%F_%N`
:0c:
${DATE}_email.txt
This will generate Berkeley mbox format, i.e. each message should have a From_ pseudo-header before the real headers; if you are not sure whether this is already the case, you should probably use procmail -Yf- to make sure to make it so (otherwise there is really no way to tell where one message ends and another begins; this applies both to your original solution, and this replacement).
Because Procmail sees the file name you are delivering to, it can infer a lockfile name now, as a minor bonus.
Using MAILDIR to specify the directory is the conventional way to do this, but you can specify a complete path to an mbox file if you prefer, of course.
I'm working with a large CSV that follows a basic process.
Backup the working original
Generate a skeleton CSV
Read from another CSV, format the contents, and then append it to the skeleton
Append the data from the backup to the new one.
The issue I'm running into is that when I read in the contents from the backup, I'm using grep -Ev -f with a file containing regexes to exclude undesired data from the backup to be included in the next revision. This currently presents a problem because grep appears to evaluate each regex in the file against every line from STDIN which will cause duplicates. The simple solution would be to simply pipe it through sort | uniq and call it a day but that will screw with the formatting of the csv currently in use. I can elaborate if needed but the short of it is I run a script to bulk process IP addresses but there is also manual editing of the file by other people and with the current form of the script the final output will be all of the automated content with manual entries being at the bottom of the file.
So, is there anyway without some ugly looping of grep to tell it to stop evaluating a line after a pattern is matched? Using -m 1 will stop grep after the first match in the whole stream where I need it stop after each new line.
For the task you want to accomplish. It would be best in my opinion to use AWK. You can find an excellent tutorial for AWK at : http://www.grymoire.com/Unix/Awk.html. You basically need to change the input field separator for awk with
awk -f',' foo.awk bar.dat
As far as the problem with sorting is concerned follow this : http://www.linuxquestions.org/questions/linux-general-1/how-to-use-awk-to-sort-243177/
I have a web application that is deployed to a server. I am trying to create a script that amoing other things reads the current version of the web application from a properties file that is deployed along with the application.
The file looks like this:
//other content
version=[version number]
build=[buildnumber]
//other content
I want to create a variable that looks like this: version-buildnumber
Here is my script for it:
VERSION_FILE=myfile
VERSION_LINE="$(grep "version=" $VERSION_FILE)"
VERSION=${VERSION_LINE#$"version="}
BUILDNUMBER_LINE=$(grep "build=" $VERSION_FILE)
BUILDNUMBER=${BUILDNUMBER_LINE#$"build="}
THEVERSION=${VERSION}-${BUILDNUMBER}
The strange thing is that this works in some cases but not in others.
The problem I get is when I am trying to concatenate the strings (i.e. the last line above). In some cases it works perfectly, but in others characters from one string replace the characters from the other instead of being placed afterwards.
It does not work in these cases:
When I read from the deployed file
If I copy the deployed file to another location and read from there
It does work in these cases:
If I write a file from scratch and read from that one.
If I create my own file and then copy the content from the deployed file into my created file.
I find this very strange. Is there someone out there recognizing this?
It is likely that your files have carriage returns in them. You can fix that by running dos2unix on the file.
You may also be able to do it on the fly on the strings you're retrieving.
Here are a couple of ways:
Do it with sed instead of grep:
VERSION_LINE="$(sed -n "/version=/{s///;s/\r//g;p}" $VERSION_FILE)"
and you won't need the Bash parameter expansion to strip the "version=".
OR
Do the grep as you have it now and do a second parameter expansion to strip the carriage return.
VERSION=${VERSION_LINE#$"version="}
VERSION=${VERSION//$'\r'}
By the way, I recommend habitually using lowercase or mixed case variable names in order to reduce the chance of name collisions.
Given this foo.txt:
//other content
version=[version number]
build=[buildnumber]
//other content
you can extract a version-build string more easily with awk:
awk -F'=' '$1 == "version" { version = $2}; $1 == "build" { build = $2}; END { print version"-"build}' foo.txt
I don't know why your script doesn't work. Can you provide an example of erroneous output?
From this sentence:
In some cases it works perfectly, but in others characters from one string replace the characters from the other instead of being placed afterwards.
I can't understand what's actually going on (I'm not a native English speaker so it's probably my fault).
Cheers,
Giacomo