I have a text file with following content
aaaa = 1000
I want to replace bbbb in LaTeX file with 1000 that I got from text file
I have tried following codes but did not work.
set motor_loc = grep -i 'aaaa' motor.txt | awk '{print $2}'
sed -i 's/bbbb/$motor_loc/' for_pdf.tex> for_pdf.tex.tmp
At this point, bbbb is changed to $motor_loc
Then, when I tried to create pdf with following line, it gives me an error.
pdflatex for_pdf.tex
How can I change bbbb to 1000 (value read from text file) instead of $motor_loc or string.
FYI, I am using Cygwin and Miktex and will try to run this code in Raspberry Pi 2.
Thank you in advance.
The single quotes in the arguments to sed keep your variable from being expanded, so go from single quotes to double quotes
user#thoth:~$ FOO=ABC
user#thoth:~$ echo $FOO
ABC
user#thoth:~$ echo "$FOO"
ABC
user#thoth:~$ echo '$FOO'
$FOO
Another sort of quotes that can also be useful are back ticks, that change the output of a command into strings.
user#thoth:~$ FOO=`ls *.txt`
user#thoth:~$ echo $FOO
soap.txt
EDIT: a different form of command substitution seems to be more commonly used in bash scripts these days
FOO=$(ls *.txt)
There are apparent differences on how backslashes are handled in the command for instance
Related
Playing with makefile and bash shell scripting where I ended-up having a variable containing:
--global-option=build_ext --global-option=--b2-args=libtorrent-python-pic=on --global-option=--b2-args=address-model=32
I need to convert it so double-quotes gets appended at the right place such as:
--global-option=build_ext --global-option=--b2-args="libtorrent-python-pic=on" --global-option=--b2-args="address-model=32"
I tried the following without success:
echo $myvar | sed -e 's/ /\n/' | sed -z '{s/=/="/2;t;s/$/"/}'
--global-option=build_ext
--global-option="--b2-args=libtorrent-python-pic=on
EDIT: Note that this time it's --b2-args= but this could be a conjunction of --anything=, and the reason why I was focussing on the second instance of = to change for =" and if true append = at the end of word.
Since your question doesn't discuss anything about prepending --global-option= if it's missing as in the final --b2-args... string on the provided input line, I think your input was really supposed to be:
$ cat file
--global-option=build_ext --global-option=--b2-args=libtorrent-python-pic=on --global-option=--b2-args=address-model=32
in which case using any sed in any shell on every Unix box:
$ sed 's/\([^ =]*=[^= ]*=\)\([^ ]*\)/\1"\2"/g' file
--global-option=build_ext --global-option=--b2-args="libtorrent-python-pic=on" --global-option=--b2-args="address-model=32"
sed does not print line 1 to line 545.The result of the following command is empty resultfile.txt. Can someone say what should be the correct command?
RESULT=545;sed -n '1, $RESULT p' Configuration.txt > resultfile.txt
The above is not a sed issue, but rather a shell issue: you used single quotes, which inhibit variable expansion.
$ echo '$PWD'
$PWD
$ echo $PWD
/tmp
$ echo "$PWD"
/tmp
Either no quotes at all, or double quotes, allows the shell to expand variables. (No quotes at all means the shell expands everything; double quotes inhibit globbing, redirections, and such.)
Use double quotes so that $RESULT is expanded:
RESULT=545;sed -n "1, $RESULT p" Configuration.txt > resultfile.txt
By the way, the following would be simpler:
head -$RESULT Configuration.txt > resultfile.txt
And, if your file is big, this will quit as soon as you reach line 545 and be more efficient:
sed ${RESULT}q Configuration.txt > resultfile.txt
i have several files in which i want to replace a certain word with the name of the file itself..
for example i have 2 files named test1.txt and test2.txt
both files are equal and look like
bla1,bla2,temp
bla2,bla3,temp
with the sed i want to replace the word temp with the name of the file itself
so after the sed operation i have 2 different files
test1.txt , which looks like :
bla1,bla2,test1
bla2,bla3,test1
test2.txt, which looks like :
bla1,bla2,test2
bla2,bla3,test2
so my question ... how do i use the actual name of the input file itself as part of the replace command?
sed "s/temp/ ??filename??/ ??? " *.txt
thanks for your suggestions
I'm not sure you can reference the filename using sed although I could be wrong. You would probably use a shell hack. A better aproach to substitute all occurrences of temp with the filename would be the following awk script:
$ awk '{gsub(/temp/,FILENAME)}1' file
use awk, awk has FILENAME variable:
awk '{sub(/temp/,FILENAME)}7' yourfile
awk 'BEGIN{FS=OFS=","} {$NF=FILENAME}1' file
The difference between this and the sub() solutions is that this will work even if the word "temp" exists elsewhere in your file, e.g. if "bla1" contains the word "temperature".
If you need to strip ".txt" from the file name as it appears from your posted desired output, tweak it to:
awk 'BEGIN{FS=OFS=","} {t=FILENAME; sub(/\.txt$/,"",t); $NF=t}1' file
You can probably edit FILENAME itself but I find it best not to mess with the builtin variables if you don't have to.
You could do it with a little bit of bash to help you out, if that's available.
find . -name "test*.txt" -type f | awk -F '/' '{print $2;}' | while read file; do sed -i "s|temp|$file|" ./$file; done
That's a kind of hacky adaptation of a script I have to do something similar. It can undoubtedly be shortened.
no sed internal variable for the file name so you need some previous batch command for a generic process
for FileName in MyFileShellFilter
do
cat <> ${FileName} | sed "s|,temp$|,${FileName}|"
done
just be carrefull with file name used, they normaly don't have \ but could have & that are s// special meaning. I use | as separator to allow / in file name but for this reason, no unescaped | are allowed in file name (normaly not)
with xargs:
printf "%s\n" *.txt | xargs -I FILE -L 1 sed 's/temp/FILE/' FILE
The filename cannot have: newlines, slashes, ampersand, single quote.
I am porting a sh script that was apparently written using GNU implementation of sed to BSD implementation of sed. The exact line in the script with the original comment are:
# escape dot in file extension to grep it
ext="$(echo $ext | sed 's/\./\\./' -)"
I am able to reproduce a results with the following (obviously I am not exhausting all possibilities values for ext) :
ext=.h; ext="$(echo $ext | sed 's/\./\\./' -)"; echo [$ext]
Using GNU's implementation of sed the following is returned:
[\.h]
Using BSD's implementation of sed the following is returned:
sed: -: No such file or directory
[]
Executing ext=.h; ext="$(echo $ext | sed 's/\./\\./')"; echo [$ext] returns [\.h] for both implementation of sed.
I have looked at both GNU and BSD's sed's man page have not found anything about the trailing "-". Googling for sed with a "-" is not very fruitful either.
Is the "-" a typo?
Is the "-" needed for some an unexpected value of $ext?
Is the issue not with sed, but rather with sh?
Can someone direct me to what I should be looking at, or even better, explain what the purpose of the "-" is?
On my system, that syntax isn't documented in the man page, but it is in the
'info' page:
sed OPTIONS... [SCRIPT] [INPUTFILE...]
If you do not specify INPUTFILE, or if INPUTFILE is -',sed'
filters the contents of the standard input.
Given that particular usage, I think you could leave off the '-' and it should
still work.
You got your specific question answered BUT your script is all wrong. Take a look at this:
# escape dot in file extension to grep it
ext="$(echo $ext | sed 's/\./\\./')"
The main problems with that are:
You're not quoting your variable ($ext) so it will go through file name expansion plus if it contains spaces will be passed to echo as multiple arguments instead of 1. Do this instead:
ext="$(echo "$ext" | sed 's/\./\\./')"
You're using an external command (sed) and a pipe to do something the shell can do trivially itself. Do this instead:
ext="${ext/./\.}"
Worst of all: You're escaping the RE meta-character (.) in your variable so you can pass it to grep to do an RE search on it as if it were a string - that doesn't make any sense and becomes intractable in the general case where your variable could contain any combination of RE metacharacters. Just do a string search instead of an RE search and you don't need to escape anything. Don't do either of the above substitution commands and then do either of these instead of grep "$ext" file:
grep -F "$ext" file
fgrep "$ext" file
awk -v ext="$ext" 'index($0,ext)' file
We have a process which can use a file containing sed commands to alter piped input.
I need to replace a placeholder in the input with a variable value, e.g. in a single -e type of command I can run;
$ echo "Today is XX" | sed -e "s/XX/$(date +%F)/"
Today is 2012-10-11
However I can only specify the sed aspects in a file (and then point the process at the file), E.g. a file called replacements.sed might contain;
s/XX/Thursday/
So obviously;
$ echo "Today is XX" | sed -f replacements.sed
Today is Thursday
If I want to use an environment variable or shell value, though, I can't find a way to make it expand, e.g. if replacements.txt contains;
s/XX/$(date +%F)/
Then;
$ echo "Today is XX" | sed -f replacements.sed
Today is $(date +%F)
Including double quotes in the text of the file just prints the double quotes.
Does anyone know a way to be able to use variables in a sed file?
This might work for you (GNU sed):
cat <<\! > replacements.sed
/XX/{s//'"$(date +%F)"'/;s/.*/echo '&'/e}
!
echo "Today is XX" | sed -f replacements.sed
If you don't have GNU sed, try:
cat <<\! > replacements.sed
/XX/{
s//'"$(date +%F)"'/
s/.*/echo '&'/
}
!
echo "Today is XX" | sed -f replacements.sed | sh
AFAIK, it's not possible. Your best bet will be :
INPUT FILE
aaa
bbb
ccc
SH SCRIPT
#!/bin/sh
STRING="${1//\//\\/}" # using parameter expansion to prevent / collisions
shift
sed "
s/aaa/$STRING/
" "$#"
COMMAND LINE
./sed.sh "fo/obar" <file path>
OUTPUT
fo/obar
bbb
ccc
As others have said, you can't use variables in a sed script, but you might be able to "fake" it using extra leading input that gets added to your hold buffer. For example:
[ghoti#pc ~/tmp]$ cat scr.sed
1{;h;d;};/^--$/g
[ghoti#pc ~/tmp]$ sed -f scr.sed <(date '+%Y-%m-%d'; printf 'foo\n--\nbar\n')
foo
2012-10-10
bar
[ghoti#pc ~/tmp]$
In this example, I'm using process redirection to get input into sed. The "important" data is generated by printf. You could cat a file instead, or run some other program. The "variable" is produced by the date command, and becomes the first line of input to the script.
The sed script takes the first line, puts it in sed's hold buffer, then deletes the line. Then for any subsequent line, if it matches a double dash (our "macro replacement"), it substitutes the contents of the hold buffer. And prints, because that's sed's default action.
Hold buffers (g, G, h, H and x commands) represent "advanced" sed programming. But once you understand how they work, they open up new dimensions of sed fu.
Note: This solution only helps you replace entire lines. Replacing substrings within lines may be possible using the hold buffer, but I can't imagine a way to do it.
(Another note: I'm doing this in FreeBSD, which uses a different sed from what you'll find in Linux. This may work in GNU sed, or it may not; I haven't tested.)
I am in agreement with sputnick. I don't believe that sed would be able to complete that task.
However, you could generate that file on the fly.
You could change the date to a fixed string, like
__DAYOFWEEK__.
Create a temp file, use sed to replace __DAYOFWEEK__ with $(date +%Y).
Then parse your file with sed -f $TEMPFILE.
sed is great, but it might be time to use something like perl that can generate the date on the fly.
To add a newline in the replacement expression using a sed file, what finally worked for me is escaping a literal newline. Example: to append a newline after the string NewLineHere, then this worked for me:
#! /usr/bin/sed -f
s/NewLineHere/NewLineHere\
/g
Not sure it matters but I am on Solaris unix, so not GNU sed for sure.