I have a file something like:
# ID 1 blah blah blah blah $ description 1 blah blah # ID 2 blah $ description 2 blah blah blah blah How can I use a sed command to delete all lines between the # and $ line? So the result will become:
# ID 1 $ description 1 blah blah # ID 2 $ description 2 blah blah blah blah Can you please kindly give an explanation as well?
Use this sed command to achieve that:
sed '/^#/,/^\$/{/^#/!{/^\$/!d}}' file.txt Mac users (to prevent extra characters at the end of d command error) need to add semicolons before the closing brackets
sed '/^#/,/^\$/{/^#/!{/^\$/!d;};}' file.txt # ID 1 $ description 1 blah blah # ID 2 $ description 2 blah blah blah blah /^#/,/^\$/ will match all the text between lines starting with # to lines starting with $. ^ is used for start of line character. $ is a special character so needs to be escaped./^#/! means do following if start of line is not #/^$/! means do following if start of line is not $d means deleteSo overall it is first matching all the lines from ^# to ^\$ then from those matched lines finding lines that don't match ^# and don't match ^\$ and deleting them using d.
extra characters at the end of d command error you need to add semicolons before the closing brackets sed '/^#/,/^\$/{/^#/!{/^\$/!d;};}' file.txt
sed '/^#/,/^\$/d' file
sed '/^====/,/^>>>>/d' file-with-git-merge-conflicts.xml > file-ok.xml to remove git merge conflict lines between '=======' and '>>>>>>> branch-name, and sed '/^<<<</d' to remove '<<<<<<< HEAD' lines (my real file was a Dia software file), but mergetool like meld should be useful !-)$ cat test 1 start 2 end 3 $ sed -n '1,/start/p;/end/,$p' test 1 start end 3 $ sed '/start/,/end/d' test 1 3 
'1,/start/p;/end/,$p' completely screwed up my workflow, as I was relying on this working. It does not work at all for me.sed '/PATTERN-1/,/PATTERN-2/{//!d}' input.txtIn general form, if you have a file with contents of form abcde, where section a precedes pattern b, then section c precedes pattern d, then section e follows, and you apply the following sed commands, you get the following results.
In this demonstration, the output is represented by => abcde, where the letters show which sections would be in the output. Thus, ae shows an output of only sections a and e, ace would be sections a, c, and e, etc.
Note that if b or d appear in the output, those are the patterns appearing (i.e., they're treated as if they're sections in the output).
Also don't confuse the /d/ pattern with the command d. The command is always at the end in these demonstrations. The pattern is always between the //.
sed -n -e '/b/,/d/!p' abcde => aesed -n -e '/b/,/d/p' abcde => bcdsed -n -e '/b/,/d/{//!p}' abcde => csed -n -e '/b/,/d/{//p}' abcde => bdsed -e '/b/,/d/!d' abcde => bcdsed -e '/b/,/d/d' abcde => aesed -e '/b/,/d/{//!d}' abcde => abdesed -e '/b/,/d/{//d}' abcde => ace
ade?
b and d and you may have contiguous start-end blocks. For the ade case, perhaps you may prefer this solution to be in the same spirit as the above answer: printf "%s\n" 1a 2bd 3c 4db 5e | sed -e '/b/,/d/{//!d;x;/./!d;s/.*//;x}' (the s/.*// is optional here, but allows several start-end blocks). But in practice, I think that this is less useful.Another approach with sed:
sed '/^#/,/^\$/{//!d;};' file /^#/,/^\$/: from line starting with # up to next line starting with $//!d: delete all lines except those matching the address patterns I did something like this long time ago and it was something like:
sed -n -e "1,/# ID 1/ p" -e "/\$ description 1/,$ p" Which is something like:
-n suppress all output-e "1,/# ID 1/ p" execute from the first line until your pattern and p (print)-e "/\$ description 1/,$ p" execute from the second pattern until the end and p (print).I might be wrong with some of the escaping on the strings, so please double check.
This might work for you (GNU sed):
sed '/^#/{:a;N;/^\$/M!ba;s/\n.*\n/\n/}' file On encountering a line beginning # gather up further lines until one beginning $, then replace everything between newlines with a newline.
Otherwise print the result.
N.B. Ranges have a flaw in that they expect both a start and end regexp. If the second regexp is not forthcoming the action of the range is still invoked i.e. if the action of the range is to delete lines, this will continue deleting lines until the end of the file.
sed is great for doing s/old/new/ on individual lines but for anything else, just use awk for clarity, simplicity, portability, robustness, etc.
Using any awk in any shell on every Unix box:
$ awk '/\$/{f=0} !f{print} /#/{f=1}' file # ID 1 $ description 1 blah blah # ID 2 $ description 2 blah blah blah blah The example below removes lines between "if" and "end if".
All files are scanned, and lines between the two matching patterns are removed ( including them ).
IFS=' ' PATTERN_1="^if" PATTERN_2="end if" # Search for the 1st pattern in all files under the current directory. GREP_RESULTS=(`grep -nRi "$PATTERN_1" .`) # Go through each result for line in "${GREP_RESULTS[@]}"; do # Save the file and line number where the match was found. FILE=${line%%:*} START_LINE=`echo "$line" | cut -f2 -d:` # Search on the same file for a match of the 2nd pattern. The search # starts from the line where the 1st pattern was matched. GREP_RESULT=(`tail -n +${START_LINE} $FILE | grep -in "$PATTERN_2" | head -n1`) END_LINE="$(( $START_LINE + `echo "$GREP_RESULT" | cut -f1 -d:` - 1 ))" # Remove lines between first and second match from file sed -e "${START_LINE},${END_LINE}d;" $FILE > $FILE done 
