I am trying to add a line to a bash script that does a bunch of other stuff and what I want it to do is write to the end of a line in another file. I have a file with a line of IP addresses which is all one line. This script that I have written asks for user input and one of those things it asks for is an IP address. That gets stored as a variable inside_ip I want to write that to the end of a line in another file. I found a similar question and the solution was
sed -i.bck '$s/$/yourText2/' list.txt
I tried to put that in a file with
sed -i.bck '$s/$/ $inside_ip/' list.txt
but it actually writes $inside_ip to the end of the file, so I just need it to print the variable.
Does the following work for you?
echo $inside_ip >> list.txt
use "'s instead of ''s as in sed -i.bck "s/$/ $inside_ip/" list.txt
Single quotes stop variables from being expanded. Double quotes allow them to be expanded. Hence:
sed -i.bck '$s/$/ '"$inside_ip/" list.txt
That protects the $s in single quotes; you want sed to see the $ and the s, not the value of your (probably unset) shell variable $s. Of course, if the file only contains one line, then the leading $ is not critical; you could leave it out, or replace it with 1. The /$/ would be left alone anyway, but the double quotes following expand the variable, preserving any spaces inside it (though IP addresses don't usually contain spaces).
Related
Here is my input file. I want to add a character ":" into the end of lines that have ">" at the beginning of the line. I tried seq -i 's|$|:|' input.txt but ":" was added to all the ending of each line. It is also hard to call out specific line numbers because, in each of my input files, the line contains">" present in different line numbers. I want to run a loop for multiple files so it is useless.
>Pas_pyrG_2
AAAGTCACAATGGTTAAAATGGATCCTTATATTAATGTCGATCCAGGGACAATGAGCCCA
TTCCAGCATGGTGAAGTTTTTGTTACCGAAGATGGTGCAGAAACAGATCTGGATCTGGGT
>Pas_rpoB_4
CAAACTCACTATGGTCGTGTTTGTCCAATTGAAACTCCTGAAGGTCCAAACATTGGTTTG
ATCAACTCGCTTTCTGTATACGCAAAAGCGAATGACTTCGGTTTCTTGGAAACTCCATAC
CGCAAAGTTGTAGATGGTCGTGTAACTGATGATGTTGAATATTTATCTGCAATTGAAGAA
>Pas_cpn60_2
ATGAACCCAATGGATTTAAAACGCGGTATCGACATTGCAGTAAAAACTGTAGTTGAAAAT
ATCCGTTCTATTGCTAAACCAGCTGATGATTTCAAAGCAATTGAACAAGTAGGTTCAATC
TCTGCTAACTCTGATACTACTGTTGGTAAACTTATTGCTCAAGCAATGGAAAAAGTAGGT
AAAGAAGGCGTAATCACTGTAGAAGAAGGCTCAGGCTTCGAAGACGCATTAGACGTTGTA
Here is experted output file:
>Pas_pyrG_2:
AAAGTCACAATGGTTAAAATGGATCCTTATATTAATGTCGATCCAGGGACAATGAGCCCA
TTCCAGCATGGTGAAGTTTTTGTTACCGAAGATGGTGCAGAAACAGATCTGGATCTGGGT
>Pas_rpoB_4:
CAAACTCACTATGGTCGTGTTTGTCCAATTGAAACTCCTGAAGGTCCAAACATTGGTTTG
ATCAACTCGCTTTCTGTATACGCAAAAGCGAATGACTTCGGTTTCTTGGAAACTCCATAC
CGCAAAGTTGTAGATGGTCGTGTAACTGATGATGTTGAATATTTATCTGCAATTGAAGAA
>Pas_cpn60_2:
ATGAACCCAATGGATTTAAAACGCGGTATCGACATTGCAGTAAAAACTGTAGTTGAAAAT
ATCCGTTCTATTGCTAAACCAGCTGATGATTTCAAAGCAATTGAACAAGTAGGTTCAATC
TCTGCTAACTCTGATACTACTGTTGGTAAACTTATTGCTCAAGCAATGGAAAAAGTAGGT
AAAGAAGGCGTAATCACTGTAGAAGAAGGCTCAGGCTTCGAAGACGCATTAGACGTTGTA
Do seq have more option to modify or the other commands can solve this problem?
sed -i '/^>/ s/$/:/' input.txt
Search the lines of input for lines that match ^> (regex for "starts with the > character). Those that do substitute : for end-of-line (you got this part right).
/ slashes are the standard separator character in sed. If you wish to use different characters, be sure to pass -e or s|$|:| probably won't work. Since / characters, unlike | characters, are not meaningful character within the shell, it's best to use them unless the pattern also contains slashes, in which case things get unwieldy.
Be careful with sed -i. Make a backup - make sure you know what's changing by using diff to compare the files.
On OSX -i requires an argument.
Using ed to edit the file:
printf "%s\n" 'g/^>/s/$/:/' w | ed -s input.txt
For every line starting with >, add a colon to the end, and then write the changed file back to disk.
I'm new to shell scripting. My requirement is to retrieve lines between two pattern, its working fine if I run it from the terminal without using variables inside sed cmd. But the problem arises when I put all those below cmd in a file and tried to execute it.
#!/bin/sh
word="ajp-qdcls2228.us.qdx.com%2F156.30.35.204-8009-34"
upto="2017-01-03 23:00"
fileC=`cat test.log`
output=`echo $fileC | sed -e "n/\$word/$upto/p"`
printf '%s\n' "$output"
If I use the below cmd in the terminal it works fine
sed -n '/ajp-qdcls2228.us.qdx.com%2F156.30.35.204-8009-34/,/2017-01-03 23:00/ p' test.log
Please suggest a workaround.
If we put aside for a moment the fact you shouldn't cat a file to a variable and then echo it for sed filtering, the reason why your command is not working is because you're not quoting the file content variable, fileC when echoing. This will munge together multiple whitespace characters and turn them into a single space. So, you're losing newlines from the file, as well as multiple spaces, tabs, etc.
To fix it, you can write:
fileC=$(cat test.log)
output=$(echo "$fileC" | sed -n "/$word/,/$upto/p")
Note the double-quotes around fileC (and a fixed sed expression, similar to your second example). Without the quotes (try echo $fileC), your fileC is expanded (with the default IFS) into a series of words, each being one argument to echo, and echo will just print those words separated with a single space. Additionally, if the file contains some of the globbing characters (like *), those patterns are also expanded. This is a common bash pitfall.
Much better would be to write it like this:
output=$(sed -n "/$word/,/$upto/p" test.log)
And if your patterns include some of the sed metacharacters, you should really escape them before using with sed, like this:
escape() {
sed 's/[^^]/[&]/g; s/\^/\\^/g' <<<"$1";
}
output=$(sed -n "/$(escape "$word")/,/$(escape "$upto")/ p" test.log)
The correct approach will be something like:
word="ajp-qdcls2228.us.qdx.com%2F156.30.35.204-8009-34"
upto="2017-01-03 23:00"
awk -v beg="$word" -v end="$upto" '$0==beg{f=1} f{print; if ($0==end) exit}' file
but until we see your sample input and output we can't know for sure what it is you need to match on (full lines, partial lines, all text on one line, etc.) or what you want to print (include delimiters, exclude one, exclude both, etc.).
I am trying to replace a specific line in a txt file with my shell script, for example;
cat aa.txt:
auditd=0
bladeServerSlot=0
When I run my script I would like to change "bladeServerSlot" to 12 as following;
cat aa.txt:
auditd=0
bladeServerSlot=12
Could you please help me?
Using sed and backreferencing:
sed -r '/bladeServerSlot/ s/(^.*)(=.*)/\1=12/g' inputfile
Using awk , this will search for the line which contains bladeServerSlot and replace the second column of that line.
awk 'BEGIN{FS=OFS="="}/bladeServerSlot/{$2=12}1' inputfile
perl -pe 's/bladeServerSlot=\K\d+/12/' aa.txt > output.txt
The \K is a particular form of the positive lookbehind, which discards all previous matches. So we need to replace only what follows. The s/ is applied by default to $_, which contains the current line. The -p prints $_ for every line, so all other lines are copied. We redirect output to a file.
Is it really necessary to replace the line in your example? As bladeServerSlot is a variable you could reset the value.
bladeServerSlot=`any command`
Or you could just let this variable be filled by a Parameter provided to this script.
bladeServerSlot=$1
With $1being the first parameter of your script. I think this would be the cleaner way do solve your issue than to do fancy regex here. The sed/perl solutions will work, but they are not very clear to other people reading your script.
Lets say I have a file which is something like this:
"Testing is important"
Nothing is impossible
The output should be:
Nothing is impossible
This means the sed removed everything before new line. Also, I need to make sure it works on bash on windows.
Please help.
You can try this
sed '1,/^\s*$/d' file
\s is whitespace, it's same with
sed '1,/^[[:blank:]]*$/d' file
Sed supports addressing lines both as numbers and as matching regex. In your case, you can delete all lines starting from 1, and ending with an empty line:
sed -e '1,/^$/d'
On Windows your files may contain contain carriage returns, in which case you can use:
sed -e '1,/^\r*$/d'
(assuming GNU sed)
To allow for more than one blank line and multiple lines after the final blank line, you could use something like this:
awk 'BEGIN{RS=ORS=""}{a=$0}END{print a}' file
This unsets the Record Separator RS, so that each block/paragraph is treated as a separate record. It assigns each record to the variable a, then prints the last value of a once the file has been processed. The Output Record Separator ORS is also unset, so that no newline is appended to the final block.
I am trying to set an IP in a file with sed. I am running this command
sed -i 's:$dbserver='':$dbserver='10.0.0.2':' t.conf
but when I look in t.conf the line is
$dbserver=10.0.0.2''
Anyone know why the two single quotes are appearing at the end of the line?
I am running Debian Linux
You need to enclose the second sed argument in double quotes:
sed -i "s:$dbserver='':$dbserver='10.0.0.2':" t.conf
This way $dbserver will be substituted with its value before being passed to sed, and the single quotes won't need escaping.
If you want $dbserver to appear literally in the conf file, preceed the dollar signs with a backslash.