Insert content into template file using bash - bash

I have a template file I want to copy and then edit from a script, inserting content at specific template points. For example, my template file might be something like,
...
rm -rf SomeDirectory
make install
#{INSERT-CONTENT-HERE}
do-something-else
...
In another script, I want to add content at "#{INSERT-CONTENT-HERE}" within a loop, i.e.
for i in c; do
# Write content to the template file copy at the correct point.
done
I think sed is the right tool, but I'm not familiar enough to know the syntax, and the man page isn't helping.

An example:
echo "Line #{INSERT-CONTENT-HERE}" | sed 's/#{INSERT-CONTENT-HERE}/---/'
To modify a file:
sed -i 's/#{INSERT-CONTENT-HERE}/---#{INSERT-CONTENT-HERE}/' filename
where -i means in-place edit so be warned
if you do:
sed -i.bak 's/#{INSERT-CONTENT-HERE}/---/' filename
it should back up original as filename.bak
also to make multiple substitutions at each line use the g flag:
sed -i.bak 's/#{INSERT-CONTENT-HERE}/---/g' filename

You can copy the output of all the commands into a temporary file and then copy the contents of that entire file into the template file:
TEMPFILE=`mktemp` && (
for i in c
echo "SomeTextBasedOn $i" >> $TEMPFILE
done
sed -i '/{INSERT-CONTENT-HERE}/r '$TEMPFILE targetfile
rm $TEMPFILE
)

Related

Script that lists all file names in a folder, along with some text after each name, into a txt file

I need to create a file that lists all the files in a folder into a text file, along with a comma and the number 15 after. For example
My folder has video.mp4, video2.mp4, picture1.jpg, picture2.jpg, picture3.png
I need the text file to read as follows:
video.mp4,15
video2.mp4,15
picture1.jpg,15
picture2.jpg,15
picture3.png,15
No spaces, just filename.ext,15 on each line. I am using a raspberry pi. I am aware that the command ls > filename.txt would put all the file names into a folder, but how would I get a ,15 after every line?
Thanks
bash one-liner:
for f in *; do echo "$f,15" >> filename.txt; done
To avoid opening the output file on each iteration you may redirect the entire output with > filename.txt:
for f in *; do echo "$f,15"; done > filename.txt
$ printf '%s,15\n' *
picture1.jpg,15
picture2.jpg,15
picture3.png,15
video.mp4,15
video2.mp4,15
This will work if those are the only files in the directory. The format specifier %s,15\n will be applied to each of printf's arguments (the names in the current directory) and they will be outputted with ,15 appended (and a newline).
If there are other files, then the following would work too, regardless of whether there are files called like this or not:
$ printf '%s,15\n' video.mp4 video2.mp4 picture1.jpg picture2.jpg "whatever this is"
video.mp4,15
video2.mp4,15
picture1.jpg,15
picture2.jpg,15
whatever this is,15
Or, on all MP4, PNG and JPEG files:
$ printf '%s,15\n' *.mp4 *.jpg *.png
video.mp4,15
video2.mp4,15
picture1.jpg,15
picture2.jpg,15
picture3.png,15
Then redirect this to a file with printf ...as above... >output.txt.
If you're using Bash, then this will not make use of any external utility, as printf is built into the shell.
You need to do something like this:
#!/bin/bash
for i in $(ls folder_name); do
echo $i",15" >> filename.txt;
done
It's possible to do this in one line, however, if you want to create a script, consider code readability in the long run.
Edit 1: better solution
As #CristianRamon-Cortes suggested in the comments below, you should not rely on the output of ls because of the problems explained in this discussion: why not parse ls. As such, here's how you should write the script instead:
#!/bin/bash
cd folder_name
for i in *; do
echo $i",15" >> filename.txt;
done
You can skip the part cd folder_name if you are already in the folder.
Edit 2: Enhanced solution:
As suggested by #kusalananda, you'd better do the redirection after done to avoid opening the file in each iteration of the for loop, so the script will look like this:
#!/bin/bash
cd folder_name
for i in *; do
echo $i",15";
done > filename.txt
Just 1 command line using 2 msr commands recusively (-r) search specific files:
msr -rp your-dir1,dir2,dirN -l -f "\.(mp4|jpg|png)$" -PAC | msr -t .+ -o '$0,15' -PIC > save-file.txt
If you want to sort by time, add --wt to first command like: msr --wt -l -rp your-dirs
Sort by size? Add --sz but only the prior one is effective if use both --sz and --wt.
If you want to exclude some directory, add like: --nd "^(test|garbage)$"
remove tail \r\n in save-file.txt : msr -p save-file.txt -S -t "\s+$" -o "" -R
See msr.exe / msr.gcc48 etc in my open project https://github.com/qualiu/msr tools directory.
A solution without a loop:
ls | xargs -i echo {},15 > filename.txt

find specific text in a directory and delete the lines from the files

I want to find specific text in a directory, and then delete the lines from the files that include the specific text.
Now I have two questions:
How can I achieve the task?
What is wrong with What I have tried? I have tried the methods below, but failed. the details are following:
grep -rnw "./" -e "webdesign"
This searches the current directory with pattern "webdesign", and I get the result:
.//pages/index.html:1:{% load webdesign %}
.//pages/pricing.html:1:{% load webdesign %}
.//prototypes.py:16: 'django.contrib.webdesign',
Then I use sed to remove the lines from those files, which doesn't work, only get blank file ( I mean it deletes all my file content):
sed -i "/webdesign/d" ./pages/index.html
or
sed "/webdesign/d" ./pages/index.html > ./pages/index.html
My software environment is: OS X Yosemite, Mac Terminal, Bash
A loop in bash will do the trick provided that there are no filenames with spaces (in which case other solutions are possible, but this is the simplest)
for i in `grep -lrnw "yourdirectory/" -e "webdesign"`
do
sed "/webdesign/d" $i > $i.tmp
# safety to avoid destroying the file if problem arises (disk full?)
if [ $? = 0 ] ; then
mv -f $i.tmp $i
fi
done
note that you should not locate this script in the current directory because it contains webdesign and it will be modified as well :)
Thanks to choroba, I know that -i option doesn't work like wished. But it has another meaning or it would be rejected by the opt parser. It has something to do with suffixes, well, it doesn't matter now, but it's difficult to see the problem at first.
Without -i you cannot work on a file in-place. And redirecting output to the input just destroys the input file (!). That's why your solution did not work.
You can install GNU sed that supports the -i option, then
sed -i '/webdesign/d' files
should work. Note that it's safer to use -i~ to create a backup.
You cannot write to the same file you're reading from, that's why
sed /webdesign/d file > file
doesn't work (it overwrites the file before you can read anything from it). Create a temporary file
sed /webdesign/d file > file.tmp
mv file.tmp file

Search text and append to each end of line of text file - OSX

I'm new to OSX command line tools.
I am trying to find a block of text in a file and append this text at the end of all lines in another text file. At run time I don't know what this text will be, I just know it will be located within "BEGINHMM" and "ENDHMM". Also, I don't know the makeup of the destination file, except for that it will not be an empty text file.
The command which finds the block of text of interest is:
sed -n '/<BEGINHMM>/,/<ENDHMM>/p' proto
where "proto" is a text file containing the text of interest.
I've been trying to pipe the output of the above command to another 'sed' command, in the following manner:
xargs -I '{}' sed -i .bak 's/$/{}/' monophones0.txt
but I am getting some bizarre results, I see the "{}" inserted in the text for example.
I've also tried piping to:
xargs -0 sed -i .bak 's/$/&/' monophones0.txt
but I just get the printout (similar to terminal echo) of the text I am trying to grab.
Ultimately I want to loop over several 'proto' files in multiple directories and copy the text between the "BEGINHMM", "ENDHMM" block in each directory, and append the selected text to that directory's monophones.txt lines.
I am running the commands in the terminal, bash, OSX 10.12.2
Any help would be appreciated.
(1) Your sed command is of the form sed -n '/A/,/B/p'; this will include the lines on which A and B occur, even if these strings do not appear at the beginning of the line. This form may have other surprises in store for you as well (what do expect will happen if B is missing or repeated?), but the remainder of this post assumes that's what you want.
(2) It's not clear how you intend to specify the "proto" files, but you do indicate they might be in several directories, so for the remainder of this post, I'll assume they are listed, one per line, in a file named proto.txt in each directory. This will ensure that you don't run into any limitations on command-line length, but the following can easily be modified if you don't want to create such a file.
(3) Here is a script which will use the sed command you've mentioned to copy segments from each of the "proto" files specified in a directory to monophones0.txt in the directory in which the script is executed.
#!/bin/bash
OUT=monophones0.txt
cat proto.txt | while read file
do
if [ -r "$file" ] ; then
sed -n '/<BEGINHMM>/,/<ENDHMM>/p' "$file" >> $OUT
elif [ -n "$file" ] ; then
echo "NOT FOUND: $file" >&2
fi
done
Just like what you did before. tmpfile=$(mktemp); sed -n '/<BEGINHMM>/,/<ENDHMM>/p' proto >$tmpfile; sed -i .bak "r $tmpfile" monophones0.txt; rm $tmpfile. This is the basic idea; there are other checks you need to perform to make this a robust script.
– 4ae1e1

Bash script to replace info in file

I have a new file that I created that has a list of all directories that have a particular file:
$ find . -name "bun.biscuts" > TREE.temp
This writes all of the correct info I need to the new temp file.
I am having trouble writing a bash script using sed to replace emails in the TREE.temp file.
This is what I have so far:
#!/bin/bash
#set -x
echo Start!
for bun.biscuts in (TREE.temp)
do
sed -i 's/EMAIL1/EMAIL2/g';
done
Any help would be amazing!
gniourf_gniourf's comment is right; you don't need to use a temporary file and loop to do this. But if you want to, you could do it like this:
while read; do
sed -i 's/EMAIL1/EMAIL2/g' "$REPLY"
done < TREE.temp
which performs the sed operation on the filename on each line of the file. $REPLY is the default variable name that each line is written to by read. You can change the variable name by doing read var instead - then each line will be written to $var.
You can use only one sed command:
sed -i.bak 's/EMAIL1/EMAIL2/g' TREE.temp
If you have node on the computer you can npm install -g rexreplace and then
rexreplace 'email1' 'email2' TREE.tmp

Unix: How can I prepend output to a file?

Specifically, I'm using a combination of >> and tee in a custom alias to store new Homebrew updates in a text file, as well as output on screen:
alias bu="echo `date "+%Y-%m-%d at %H:%M"` \
>> ~/Documents/Homebrew\ Updates.txt && \
brew update | tee -a ~/Documents/Homebrew\ Updates.txt"
Question: What if I wish to prepend this output in my textfile, i.e. placed at the beginning of the file as opposed to appending it to the end?
Edit1: As someone reported in the answers below, the use of temp files might be a good approach, which at least helped me partially:
targetLog="~/Documents/Homebrew\ Updates.txt"
alias bu="(brew update | cat - $targetLog \
> /tmp/out1 && mv /tmp/out1 $targetLog \
&& echo `date "+%Y-%m-%d at %H:%M":%S` | \
cat - $targetLog > /tmp/out2 \
&& mv /tmp/out2 $targetLog)"
But the problem is the output to STDOUT (previously made possible by tee), which I'm not sure can be incorporated in this tempfile approach …?
sed will happily do that for you, using -i to edit in place, eg.
sed -i -e "1i `date "+%Y-%m-%d at %H:%M"`" some_file
This works by creating an output file:
Let's say we have the initial contents on file.txt
echo "first line" > file.txt
echo "second line" >> file.txt
So, file.txt is our 'bottom' text file. Now prepend into a new 'output' file
echo "add new first line" | cat - file.txt > output.txt # <--- Just this command
Now, output has the contents the way we want. If you need your old name:
mv output.txt file.txt
cat file.txt
The only simple and safe way to modify an input file using bash tools, is to use a temp file, eg. sed -i uses a temp file behind the scenes (but to be robust sed needs more).
Some of the methods used have a subtle "can break things" trap, when, rather than running your command on the real data file, you run it on a symbolic link (to the file you intend to modify). Unless catered for correctly, this can break the link and convert it into a real file which receives the mods and leaves the original real file without the intended mods and without the symlink (no error exit-code results)
To avoid this with sed, you need to use the --follow-symlinks option.
For other methods, just be aware that it needs to follow symlinks (when you act on such a link)
Using a temp file, then rm temp file works only if "file" is not a symlink.
One safe way is to use sponge from package moreutils
Unlike a shell redirect, sponge soaks up all its input before
opening
the output file. This allows for constructing pipelines that read from
and write to the same file.
sponge is a good general way to handle this type of situation.
Here is an example, using sponge
hbu=~/'Documents/Homebrew Updates.txt'
{ date "+%Y-%m-%d at %H:%M"; cat "$hbu"; } | sponge "$hbu"
Simplest way IMO would be to use echo and cat:
echo "Prepend" | cat - inputfile > outputfile
Or for your example basically replace the tee -a ~/Documents/Homebrew\ Updates.txt with cat - ~/Documents/Homebrew\ Updates.txt > ~/Documents/Homebrew\ Updates.txt
Edit: As stated by hasturkun this won't work, try:
echo "Prepend" | cat - file | tee file
But this isn't the most efficient way of doing it any more...
Similar to the accepted answer, however if you are coming here because you want to prepend to the first line - rather than prepend an entirely new line - then use this command.
sed -i "1 s/^/string_replacement/" some_file
The -i flag will do a replacement within the file (rather than creating a new file).
Then the 1 will only do the replacement on line 1.
Finally, the s command is used which has the following syntax s/find/replacement/flags.
In our case we don't need any flags. The ^ is called a caret and it is used to represent the very start of a string.
Try this http://www.unix.com/shell-programming-scripting/42200-add-text-beginning-file.html
There is no direct operator or command AFAIK.You use echo, cat, and mv to get the effect.
{ date; brew update |tee /dev/tty; cat updates.txt; } >updates.txt.new
mv updates.txt.new updates.txt
I've no idea why you want to do this. It's pretty standard that logs like this have later entries appearing, well, later in the file.

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