i try to write a very simple bash file that allow my to open and modify n times a file.java .
The modification i want is only a change in a single (or two) row of a single number.
I try to do this with the follow code:
#!/bin/bash
# commento
touch ic.java
touch input
n=0
for n in "1" "2" "3" "4.5"
do
echo 'import java.io.*;'>ic.java
echo 'import java.util.*;'>>ic.java
echo ' '>>ic.java
echo 'class INITIAL_CONDITION_NORMAL {'>>ic.java
echo 'public static void main (String args[]) {'>>ic.java
echo "$n">>ic.java
n=$(($n+1))
echo '....'>>ic.java
done
java ic.java
as you see i must write all the file and, when i like to change the number, put the "$n"
and n=$(($n+1)) in the row then go on until the end of the file and lounch it (java ic.java).
I know i can use something like:
sed -i 'm-th_row/old/new/' ic.java
but if i want to do this recursively (100 times) whit every time a different new value (as in the example) how can i do that?
Thanks a lot for Your help !
As long as new contains no / (slash) character, or any other special character that would confuse sed, this is the sort of pattern you need.
for n in "1" "2" "3" "4.5"
sed -i "m-th_row/old/$n/" ic.java
done
Of course, that snippet would just modify the same file repeatedly, which probably wouldn't be helpful, but you get the idea.
Related
I'm a beginner in bash and here is my problem. I have a file just like this one:
Azzzezzzezzzezzz...
Bzzzezzzezzzezzz...
Czzzezzzezzzezzz...
I try in a script to edit this file.ABC letters are unique in all this file and there is only one per line.
I want to replace the first e of each line by a number who can be :
1 in line beginning with an A,
2 in line beginning with a B,
3 in line beginning with a C,
and I'd like to loop this in order to have this type of result
Azzz1zzz5zzz1zzz...
Bzzz2zzz4zzz5zzz...
Czzz3zzz6zzz3zzz...
All the numbers here are random int variables between 0 and 9. I really need to start by replacing 1,2,3 in first exec of my loop, then 5,4,6 then 1,5,3 and so on.
I tried this
sed "0,/e/s/e/$1/;0,/e/s/e/$2/;0,/e/s/e/$3/" /tmp/myfile
But the result was this (because I didn't specify the line)
Azzz1zzz2zzz3zzz...
Bzzzezzzezzzezzz...
Czzzezzzezzzezzz...
I noticed that doing sed -i "/A/ s/$/ezzz/" /tmp/myfile will add ezzz at the end of A line so I tried this
sed -i "/A/ 0,/e/s/e/$1/;/B/ 0,/e/s/e/$2/;/C/ 0,/e/s/e/$3/" /tmp/myfile
but it failed
sed: -e expression #1, char 5: unknown command: `0'
Here I'm lost.
I have in a variable (let's call it number_of_e_per_line) the number of e in either A, B or C line.
Thank you for the time you take for me.
Just apply s command on the line that matches A.
sed '
/^A/{ s/e/$1/; }
/^B/{ s/e/$2/; }
# or shorter
/^C/s/e/$3/
'
s command by default replaces the first occurrence. You can do for example s/s/$1/2 to replace the second occurrence, s/e/$1/g (like "Global") replaces all occurrences.
0,/e/ specifies a range of lines - it filters lines from the first up until a line that matches /e/.
sed is not part of Bash. It is a separate (crude) programming language and is a very standard command. See https://www.grymoire.com/Unix/Sed.html .
Continuing from the comment. sed is a poor choice here unless all your files can only have 3 lines. The reason is sed processes each line and has no way to keep a separate count for the occurrences of 'e'.
Instead, wrapping sed in a script and keeping track of the replacements allows you to handle any file no matter the number of lines. You just loop and handle the lines one at a time, e.g.
#!/bin/bash
[ -z "$1" ] && { ## valiate one argument for filename provided
printf "error: filename argument required.\nusage: %s filename\n" "./$1" >&2
exit 1
}
[ -s "$1" ] || { ## validate file exists and non-empty
printf "error: file not found or empty '%s'.\n" "$1"
exit 1
}
declare -i n=1 ## occurrence counter initialized 1
## loop reading each line
while read -r line || [ -n "$line" ]; do
[[ $line =~ ^.*e.*$ ]] || continue ## line has 'e' or get next
sed "s/e/1/$n" <<< "$line" ## substitute the 'n' occurence of 'e'
((n++)) ## increment counter
done < "$1"
Your data file having "..." at the end of each line suggests your files is larger than the snippet posted. If you have lines beginning 'A' - 'Z', you don't want to have to write 26 separate /match/s/find/replace/ substitutions. And if you have somewhere between 3 and 26 (or more), you don't want to have to rewrite a different sed expression for every new file you are faced with.
That's why I say sed is a poor choice. You really have no way to make the task a generic task with sed. The downside to using a script is it will become a poor choice as the number of records you need to process increase (over 100000 or so just due to efficiency)
Example Use/Output
With the script in replace-e-incremental.sh and your data in file, you would do:
$ bash replace-e-incremental.sh file
Azzz1zzzezzzezzz...
Bzzzezzz1zzzezzz...
Czzzezzzezzz1zzz...
To Modify file In-Place
Since you make multiple calls to sed here, you need to redirect the output of the file to a temporary file and then replace the original by overwriting it with the temp file, e.g.
$ bash replace-e-incremental.sh file > mytempfile && mv -f mytempfile file
$ cat file
Azzz1zzzezzzezzz...
Bzzzezzz1zzzezzz...
Czzzezzzezzz1zzz...
I need to create Bash script that generates text files named file001.txt through file050.txt
Of those files, all should have this text inserted "This if file number xxx" (where xxx is the assigned file number), except for file007.txt, which needs to me empty.
This is what I have so far..
#!/bin/bash
touch {001..050}.txt
for f in {001..050}
do
echo This is file number > "$f.txt"
done
Not sure where to go from here. Any help would be very appreciated.
#!/bin/bash
for f in {001..050}
do
if [[ ${f} == "007" ]]
then
# creates empty file
touch "${f}.txt"
else
# creates + inserts text into file
echo "some text/file" > "${f}.txt"
fi
done
The continue statement can be used to skip an iteration of a loop and go on to the next -- though since you actually do want to take an operation on file 7 (creating it), it makes just as much sense to have a conditional:
for (( i=1; i<50; i++ )); do
printf -v filename '%03d.txt' "$i"
if (( i == 7 )); then
# create file if it doesn't exist, truncate if it does
>"$filename"
else
echo "This is file number $i" >"$filename"
fi
done
A few words about the specific implementation decisions here:
Using touch file is much slower than > file (since it starts an external command), and doesn't truncate (so if the file already exists it will retain its contents); your textual description of the problem indicates that you want 007.txt to be empty, making truncation appropriate.
Using a C-style for loop, ie. for ((i=0; i<50; i++)), means you can use a variable for the maximum number; ie. for ((i=0; i<max; i++)). You can't do {001..$max}, by contrast. However, this does need meaning to add zero-padding in a separate step -- hence the printf.
Of course, you can costumize the files' name and the text, the key thing is the ${i}. I tried to be clear, but let us know if you don't understand something.
#!/bin/bash
# Looping through 001 to 050
for i in {001..050}
do
if [ ${i} == 007 ]
then
# Create an empty file if the "i" is 007
echo > "file${i}.txt"
else
# Else create a file ("file012.txt" for example)
# with the text "This is file number 012"
echo "This is file number ${i}" > "file${i}.txt"
fi
done
I have a text file in which each a first block of text on each line is separated by a tab from a second block of text like so:
VERBS, AUXILIARY. "Be," subjunctive and quasi-subjunctive Be, Beest, &c., was used in A.-S. (beon) generally in a future sense.
In case it is hard to tell, tab is long space between "quasi-subjunctive" and "Be".
So I am thinking off the top of my head a 'for' loop in which a var is set using 'sed' to read the first block of text of a line, upto and including the tab (or not, doesn't really matter) and then the 'var' is used to find subsequent matches adding a "(x)" right before the tab to make the line unique. The 'x' of course would be a running counter numbering the first instance '1' incrementing and then each subsequent match one number higher.
One problem I see is stopping 'sed' after each subsequent match so the counter can be incremented. Is there a way to do this, since it is "sed's" normal behaviour to continue on thru without stop (as far as I know) until all lines are processed.
You can set the IFS to TAB character and read the line into variables. Something like:
$ while IFS=$'\t' read block1 block2;do
echo "block1 is $block1"
echo "block2 is $block2"
done < file
block1 is VERBS, AUXILIARY. "Be," subjunctive and quasi-subjunctive
block2 is Be, Beest, &c., was used in A.-S. (beon) generally in a future sense.
Ok so I got the job done with this little (or perhaps big if too much overkill?) script I whipped up:
#!/bin/bash
sedLnCnt=1
while [[ "$sedLnCnt" -lt 521 ]] ; do
lN=$(sed -n "${sedLnCnt} p" sGNoSecNums.html|sed -r 's/^([^\t]*\t).*$/\1/') #; echo "\$lN: $lN"
lnNum=($(grep -n "$lN" sGNoSecNums.html|sed -r 's/^([0-9]+):.*$/\1/')) #; echo "num of matches: ${#lnNum[#]}"
if [[ "${#lnNum[#]}" -gt 1 ]] ; then #'if'
lCnt="${#lnNum[#]}"
((eleN = $lCnt-1)) #; echo "\$eleN: ${eleN}" # var $eleN needs to be 1 less than total line count of zero-based array
while [[ "$lCnt" -gt 0 ]] ; do
sed -ri "${lnNum[$eleN]}s/^([^\t]*)\t/\1 \(${lCnt}\)\t/" sGNoSecNums.html
((lCnt--))
((eleN--))
done
fi
((sedLnCnt++))
done
Grep was the perfect way to find line numbers of matches, jamming them into an array and then editing each line appending the unique identifier.
For example:
((
extract everything here, ignore the rest
))
I know how to ignore everything within, but I don't know how to do the opposite. Basically, it'll be a file and it needs to extract the data between the two points and then output it to another file. I've tried countless approaches, and all seem to tell me the indentation I'm stating doesn't exist in the file, when it does.
If somebody could point me in the right direction, I'd be grateful.
If your data are "line oriented", so the marker is alone (as in the example), you can try some of the following:
function getdata() {
cat - <<EOF
before
((
extract everything here, ignore the rest
someother text
))
after
EOF
}
echo "sed - with two seds"
getdata | sed -n '/((/,/))/p' | sed '1d;$d'
echo "Another sed solution"
getdata | sed -n '1,/((/d; /))/,$d;p'
echo "With GNU sed"
getdata | gsed -n '/((/{:a;n;/))/b;p;ba}'
echo "With perl"
getdata | perl -0777 -pe "s/.*\(\(\s*\\n(.*)?\)\).*/\$1/s"
Ps: yes, its looks like a dance of crazy toothpicks
Assuming you want to extract the string inside (( and )):
VAR="abc((def))ghi"
echo "$VAR"
VAR=${VAR##*((}
VAR=${VAR%%))*}
echo "$VAR"
## cuts away the longest string from the beginning; # cuts away the shortest string from the beginning; %% cuts away the longest string at the end; % cuts away the shortes string at the end
The file :
$ cat /tmp/l
((
extract everything here, ignore the rest
someother text
))
The script
$ awk '$1=="((" {p=1;next} $1=="))" {p=o;next} p' /tmp/l
extract everything here, ignore the rest
someother text
sed -n '/^((/,/^))/ { /^((/b; /^))/b; p }'
Brief explanation:
/^((/,/^))/: range addressing (inclusive)
{ /^((/b; /^))/b; p }: sequence of 3 commands
1. skip line with ^((
2. skip line with ^))
3. print
The line skipping is required to make the range selection exclusive.
Hey, I'm trying to get zsh to run a git command, and use the output to generate autocomplete possibilities.
The command I'm trying to run is
git log -n 2 --pretty=format:"'%h %an'"
And here's the code I'm using:
local lines words
lines=(${(f)$(git log -n 2 --pretty=format:"'%h %an'")})
words=${(f)$(_call_program foobar git log -n 2 --pretty=format:"%h")}
echo "Length of lines is " ${#lines[#]} " value is " ${lines}
echo "Length of words is " ${#words[#]} " value is " ${words}
compadd -d lines -a -- words
This doesn't work at all...it thinks that words is a single element and lines aren't getting printed properly at all.
However, when I try to setup an array of strings by hand, it all works.
local lines words
lines=('one two' 'three')
words=('one two' 'three')
echo "Length of lines is " ${#lines[#]} " value is " ${lines}
echo "Length of words is " ${#words[#]} " value is " ${words}
compadd -d lines -a -- words
To force words being an array, you should use either
words=( ${(f)...} )
or
set -A words ${(f)...}
. If you use just words=${(f)...}, you will always get one value. By the way, why have you added parenthesis around ${(f)...} when you were writing lines definition, but have not done it for words?
Also, there is another thing to concern: ${(f)$(...)} should be replaced with ${(f)"$(...)"}. It is some black magic here: I don't know why first one does emit a single scalar value, while second one does emit an array of scalar values, just was pointed to this fact by someone here on stackoverflow.
Thanks for the help, ZyX, here's the final script for anyone who cares
local lines words
lines=(${(f)"$(git log -n 15 --pretty=format:"'%h - %an - %s'")"} )
words=(${(f)"$(git log -n 15 --pretty=format:"%h")"})
compadd -l -d lines -a -- words
I had a more complicated situation. I was trying to grep many files for a string, then edit the resulting list of files. The use of ** and * wildcards didn't let the above solution work for me. I did get it to work by breaking up into 2 steps:
> tmp=$(grep -l someString **/*.clj)
> fileList=( ${(f)tmp} )