I'm trying to replace a single line in a file with the content of another file, and print the result.
#!/bin/sh
set -e
echo "a
b
c" > template.txt
echo "Hello, World!" > foo.txt
sed -e '/b/ {
d
r /dev/stdin
}' "template.txt" < "foo.txt"
Unfortunately this results in
a
c
and when I remove the d line in the sed script, I can get
a
b
Hello, World
c
How can I get rid of the b and preserve Hello, World?
Thanks, ToxicFrog, for the answer. Apparently, d means "clear pattern space and proceed immediately to next line", so I need these commands in the opposite order. r appends the contents of the file to the output immediately rather than reading it into the pattern space.
sed -e '/b/ {
r /dev/stdin
d
}' "template.txt" < "foo.txt"
This might work for you (GNU sed):
sed '/b/cHello World!' file
Change (c) any line containing b to Hello World!.
Related
I can print the current filename with GNU sed using "F". I can make changes to the pattern space with "s" (and other commands). Is there any way to put the filename into the pattern space so I can manipulate this as well.
For example:
09:24:25:~ $ sed -n 'F ; s/hello/goodbye/ig ; p' hello.txt
hello.txt
goodbye world
09:24:42:~ $
Is there a thing I could put instead of "F" which would get this to result in:
goodbye.txt
goodbye world
Piping back to sed should work
$ sed 'F' hello.txt | sed -n 's/hello/goodbye/p'
goodbye.txt
goodbye world
This can be done in a single gnu awk like this:
awk -v IGNORECASE=1 '
NR==1{$0 = FILENAME "\n" $0} {gsub(/hello/, "goodbye")} 1' hello.txt
goodbye.txt
goodbye world
This might work for you (GNU sed):
sed '1{h;s/.*/sed -n 1F file/e;x};G' file
This appends the file name to each line i.e. the file name is held in the hold space.
For line one only, copy current pattern space to the hold space. Replace the line by another sed scripts output which evaluates to the current file name. Swap the hold space for the pattern space.
For each line append the hold space.
How to force sed to print what it does with my file?
My text01.txt file:
aaa
bbb
ccc
ddd
c
ee
My code:
sed -i 's/c/X/g' ./text01.txt
I want to get in terminal something like this:
sed: line 3 change ccc to XXX
sed: line 5 change c to X
sed -i"bak" 's/c/X/g' text01.txt && diff text01.txt text01.txtbak
will give you a diff summary. like:
3c3
< XXX
---
> ccc
5c5
< X
---
> c
You can read diff man page, to adjust the diff output, e.g. with -c/-u/-y... options as you like.
If you want to get exactly same format you described, you can do some work on diff output as well.
This comes pretty close to your requirement:
$ paste <(cat -n text01.txt) <(sed 's/c/X/g' ./text01.txt)
1 aaa aaa
2 bbb bbb
3 ccc XXX
4 ddd ddd
5 c X
6 ee ee
cat -n prepends line numbers, and the paste command with process substitution prints the file and the sed output next to each other.
Or, more elaborate, with awk:
awk '{ getline mod_line < ARGV[2]
if ($0 != mod_line) {
printf "sed line %d change %s to %s\n", NR, $0, mod_line }
}' text01.txt <(sed 's/c/X/g' text01.txt)
This reads, for each line of text01.txt, the corresponding line as modified by sed. If they are different, the line number and both lines get printed:
sed line 3 change ccc to XXX
sed line 5 change c to X
plus an awk warning because it tries to close an anonymous pipe – this can be suppressed by redirecting stderr, i.e., appending 2> /dev/null to the command.
The closest thing to sed "built-in" debugging is the l command, which prints the current content of the pattern space. If you'd like to go all in, there are proper debuggers, for example sedsed.
This might work for you (GNU sed):
sed -i -e 'h;/c/!b;s//X/g;H;x;s/\n/ to /;s/^/sed: changed /w/dev/stdout' -e 'x' file
This makes a copy of each line in the hold space (HS) and if the substitution pattern does not match, no further action takes place. Otherwise, the substitution is made on the line in the pattern space (PS) and this is appended to the HS. Focus is then changed to the HS and format of before and after effected. The formated line is then written out to the standard output i.e. the terminal and finally focus is reverted to the PS so that the substituted line is included in the original updated file.
This code removes newlines, then quotes and separates the characters.
Semicolon isn't working. Piping to a second sed does work, but the semicolon doesn't.
Script
# Piping works
echo "$1" | sed -r ':a;N;s/\n/\\n/;$!ba' | sed -r 's/(\\?.)/'"'\1',/g"
# Semicolon doesn't work on single lines
echo "$1" | sed -r ':a;N;s/\n/\\n/;$!ba;s/(\\?.)/'"'\1',/g"
# Skipping N command on single line works
echo "$1" | sed -r ':a;$bb;N;s/\n/\\n/;$!ba;:b;s/(\\?.)/'"'\1',/g"
Output:
$ wchar "test\n"
't','e','s','t','\n',
test\n
't','e','s','t','\n',
$ wchar "test
test"
't','e','s','t','\n','t','e','s','t',
't','e','s','t','\n','t','e','s','t',
't','e','s','t','\n','t','e','s','t',
The problem you run into is that the first line is also the last one (note that "test\n" does not contain a newline but a backslash), so the first N command is executed before any test whether the current line is the last one and ends up trying to fetch past the end.
Since all you're trying to do with the label and N loop is to assemble the file into the hold buffer (the replacement of the newlines can wait until afterwards), I suggest the following replacement:
echo -e "test\n" | sed -rn '1h;1!H;${x;s/\n/\\n/g; s/(\\?.)/'\''\1'\'', /g;p}'
This follows the basic pattern
sed -n '1 h; 1! H; $ { x; do stuff; p }'
...in other words, it reads the file into the hold buffer, swaps it back into the pattern space when the last line is being handled (i.e., when the whole file is in the hold buffer), does stuff with it and then prints the result. The s commands in place of do stuff are lifted from your code.
I have 'file1' with (say) 100 lines. I want to use sed or awk to print lines 23, 71 and 84 (for example) to 'file2'. Those 3 line numbers are in a separate file, 'list', with each number on a separate line.
When I use either of these commands, only line 84 gets printed:
for i in $(cat list); do sed -n "${i}p" file1 > file2; done
for i in $(cat list); do awk 'NR==x {print}' x=$i file1 > file2; done
Can a for loop be used in this way to supply line addresses to sed or awk?
This might work for you (GNU sed):
sed 's/.*/&p/' list | sed -nf - file1 >file2
Use list to build a sed script.
You need to do > after the loop in order to capture everything. Since you are using it inside the loop, the file gets overwritten. Inside the loop you need to do >>.
Good practice is to or use > outside the loop so the file is not open for writing during every loop iteration.
However, you can do everything in awk without for loop.
awk 'NR==FNR{a[$1]++;next}FNR in a' list file1 > file2
You have to >>(append to the file) . But you are overwriting the file. That is why, You are always getting 84 line only in the file2.
Try use,
for i in $(cat list); do sed -n "${i}p" file1 >> file2; done
With sed:
sed -n $(sed -e 's/^/-e /' -e 's/$/p/' list) input
given the example input, the inner command create a string like this: `
-e 23p
-e 71p
-e 84p
so the outer sed then prints out given lines
You can avoid running sed/awk in a for/while loop altgether:
# store all lines numbers in a variable using pipe
lines=$(echo $(<list) | sed 's/ /|/g')
# print lines of specified line numbers and store output
awk -v lineS="^($lines)$" 'NR ~ lineS' file1 > out
I need to replace the pattern ### with the current line number.
I managed to Print in the next line with both AWK and SED.
sed -n "/###/{p;=;}" file prints to the next line, without the p;, it replaces the whole line.
sed -e "s/###/{=;}/g" file used to make sense in my head, since the =; returns the line number of the matched pattern, but it will return me the the text {=;}
What am i Missing? I know this is a silly question. I couldn't find the answer to this question in the sed manual, it's not quite clear.
If possible, point me what was i missing, and what to make it work. Thank you
Simple awk oneliner:
awk '{gsub("###",NR,$0);print}'
Given the limitations of the = command, I think it's easier to divide the job in two (actually, three) parts. With GNU sed you can do:
$ sed -n '/###/=' test > lineno
and then something like
$ sed -e '/###/R lineno' test | sed '/###/{:r;N;s/###\([^\n]*\n\)\([^\n]*\)/\2\1/;tr;:c;s/\n\n/\n/;tc}'
I'm afraid there's no simple way with sed because, as well as the = command, the r and GNU extension R commands don't read files into the pattern space, but rather directly append the lines to the output, so the contents of the file cannot be modified in any way. Hence piping to another sed command.
If the contents of test are
fooo
bar ### aa
test
zz ### bar
the above will produce
fooo
bar 2 aa
test
zz 4 bar
This might work for you (GNU sed):
sed = file | sed 'N;:a;s/\(\(.*\)\n.*\)###/\1\2/;ta;s/.*\n//'
An alternative using cat:
cat -n file | sed -E ':a;s/^(\s*(\S*)\t.*)###/\1\2/;ta;s/.*\t//'
As noted by Lev Levitsky this isn't possible with one invocation of sed, because the line number is sent directly to standard out.
You could have sed write a sed-script for you, and do the replacement in two passes:
infile
a
b
c
d
e
###
###
###
a
b
###
c
d
e
###
Find the lines that contain the pattern:
sed -n '/###/=' infile
Output:
6
7
8
11
15
Pipe that into a sed-script writing a new sed-script:
sed 's:.*:&s/###/&/:'
Output:
6s/###/6/
7s/###/7/
8s/###/8/
11s/###/11/
15s/###/15/
Execute:
sed -n '/###/=' infile | sed 's:.*:&s/^/& \&/:' | sed -f - infile
Output:
a
b
c
d
e
6
7
8
a
b
11
c
d
e
15
is this ok ?
kent$ echo "a
b
c
d
e"|awk '/d/{$0=$0" "NR}1'
a
b
c
d 4
e
if match pattern "d", append line number at the end of the line.
edit
oh, you want to replace the pattern not append the line number... take a look the new cmd:
kent$ echo "a
b
c
d
e"|awk '/d/{gsub(/d/,NR)}1'
a
b
c
4
e
and the line could be written like this as well: awk '1+gsub(/d/,NR)' file
one-liner to modify the FILE in place, replacing LINE with the corresponding line number:
seq 1 `wc -l FILE | awk '{print $1}'` | xargs -IX sed -i 'X s/LINE/X/' FILE
Following on from https://stackoverflow.com/a/53519367/29924
If you try this on osx the version of sed is different and you need to do:
seq 1 `wc -l FILE | awk '{print $1}'` | xargs --verbose -IX sed -i bak "X s/__line__/X/" FILE
see https://markhneedham.com/blog/2011/01/14/sed-sed-1-invalid-command-code-r-on-mac-os-x/