I just blindly followed a command from a tutorial to rename several folders at a time. Can anyone explain the meaning of "p;s" given as the argument to sed's -e option.
[root#LinuxD delsure]# ls
ar1 ar2 ar3 ar4 ar5 ar6 ar7
[root#LinuxD delsure]# find . -type d -name "ar*"|sed -e "p;s/ar/AR/g"|xargs -n2 mv
[root#LinuxD delsure]# ls
AR1 AR2 AR3 AR4 AR5 AR6 AR7
A sed script (the bit following the -e option) can contain multiple commands, separated by ;
The script in your example uses the p command to print the pattern space (i.e. the line just read from the input) followed by the s command to perform a substitution on the pattern space.
By default (unless the pattern space is cleared or the -n option is given to sed) after processing each line the current pattern spaceline is printed again, so the result of the substitution will be printed.
Another way to write the same thing would be:
sed -e "p" -e "s/ar/AR/g"
This separates the commands into two scripts. Another way would be:
sed "p;s/ar/AR/g"
because if the only argument to sed is a script then the -e option is not needed
The argument to the -e option is a script consisting of two commands. The first is p, which prints the unadulterated input, the second is a standard, global substitution. So for input ar1, this should output
ar1
AR1
The other part of this trick is the -n2 option on xargs, which forces it to only use two arguments at a time (instead of as many as it can handle, which would produce very different results).
One way in bash:
$ ls
ar6 ar7
$ find . -name 'ar*' | while IFS= read -r file; do echo mv "$file" "${file^^}"; done
mv ./ar6 ./AR6
mv ./ar7 ./AR7
get rid of the "echo" when you're happy with the output.
Related
I have nearly 300 files in 60 folders .
As per the C++ coding guidelines, I need to replace below lines from *.cpp and *.cl files (wants to remove extra space between if and for statement) -
for (* .....)
with
for(* .....)
and also
if (* .....)
with
if(* .....)
Can any one suggest me the grep command to do search and replace for all files.
Edited:
I tried with below commands:
sed -i 's/for (/for(/g' *.cpp
But got error like below:
sed: can't read *.cpp: No such file or directory
I think you need sed command (stream editor, see man sed on your mashine). It is more suitable for file editing.
sed -i -E 's/(for|if)[ ]+(\(.*\))/\1\2/g'
Let me explain:
-i stands for inline, that means that all changes will be done and saved in the file
-E is needed to use extended regular expression inside with sed
s/(for|if)[ ]+(\(.*\))/\1\2/g
s stands for substitute
/ is a separator, which separates different parts of command. Between first / and second / there is pattern that you need to find (and then replace). After second / and third / there that we want to have after substitution.
g in the end stands for global, that means to make changes in the whole file.
How to apply to every file that you need?
This question is already exist, so in the end you need to run in directory where are your files stored following command
find ./ -type f -exec sed -i -E 's/(for|if)[ ]+(\(.*\))/\1\2/g' {} \;
I hope, this will help:)
I have created the file "brol.txt", with following content:
for (correct
for(wrong
if (correct
if(wrong
I have launched following grep command:
grep -E "for \(|if \(" brol.txt
With following result:
for (correct
if (correct
Explanation:
grep -E means extended grep (allows to search for expression1 OR expression2,
separated by a pipe character)
\( means the search for a round bracket. The backslash is an escape character.
I would like to execute this make command to first replace the first line of all csv files inside the directory and then replace the # for commas through the other lines.
The second command is working fine and does what it is supposed to do, but the first one only replaces the line on the first file.
Could anyone give me a help on that?
csv:
$(DOCKER_RUN) npm run csv-generator
make format-csv
format-csv:
#sed -i '' '1 s/^.*$$/"bar","repository"/g' $(CURDIR)/foo/npm/*.csv
#sed -i '' 's/\(.*\)#/\1","/g' $(CURDIR)/foo/npm/*.csv
The reason that the first sed command "fails" is that sed doesn't reset the line counter between input files (on your system, and neither on my Mac OS X machine, see comments):
$ cat test1
a
b
g
$ cat test2
aa
bb
cc
$ sed -n '=' test1 test2 # the '=' sed command outputs line numbers
1
2
3
4
5
6
This is why the first sed command isn't doing what you want it to do, it only affects the first file's first line.
The solution is to loop over the files and call sed for each of them (untested in Makefile):
#for f in $(CURDIR)/foo/npm/*.csv; do \
sed -i '' '1 s/^.*$$/"bar","repository"/g' $f; \
done
Using find and xargs will also work, just make sure that find isn't picking up files further down in the folders.
EDIT: In light of the comments on this answer, I would recommend avoiding the use of sed -i on multiple files altogether, and convert both statements into for-loops (in this case, they may be collapsed into one loop with two statements):
#for f in $(CURDIR)/foo/npm/*.csv; do \
sed -i '' '1 s/^.*$$/"bar","repository"/g' $f; \
sed -i '' 's/\(.*\)#/\1","/g' $f; \
done
In my experience, using for-loops in Makefiles seems to be far more common compared to using find and xargs. This is probably due to incompatibility between find and xargs versions between Unices. It also makes the Makefile a lot easier to read if one uses explicit loops.
I managed to solve with:
#find $(CURDIR)/foo/npm -name "*.csv" -type f | xargs -L 1 sed -i '' '1 s/^.*$$/"bar"/g'
I have a bash script in which I have a few qsubs. Each of them are waiting for a preivous qsub to be done before starting.
My first qsub consist of sending files in a certain directory to a perl program and having the outfiles printed in a new directory. At the end, I echo the array with all my jobs names. This script works as intented.
mkdir -p /perl_files_dir
for ID_FILES in `ls Infiles_dir/*.txt`;
do
JOB_ID=`echo "perl perl_scirpt.pl $ID_FILES" | qsub -j oe `
JOB_ID_ARRAY="${JOB_ID_ARRAY}:$JOB_ID"
done
echo $JOB_ID_ARRAY
My second qsub is meant to sort all my previous files made with my perl script in a new outfile and to start after all these jobs are done (about 100 jobs) with depend=afterany. Again, this part is working fine.
SORT_JOB=`echo "sort -m -n perl_files_dir/*.txt >>sorted_file.txt" | qsub -j oe -W depend=afterany$JOB_ID_ARRAY`
SORT_ARRAY="${SORT_ARRAY}:$SORT_JOB"
My issue is that in my sorted file, I have a few columns I wish to remove (2 to 6), so I came up with this last line using awk piped to sed with another depend=afterany
SED=`echo "awk '{\$2="";\$3="";\$4="";\$5="";\$6=""; print \$0}' sorted_file.txt \
| sed 's/ //g' >final_file.txt" | qsub -j oe -W depend=afterany$SORT_ARRAY`
This last step creates final_file.txt, but leaves it empty. I added SED= before my echo because it would otherwise give me Command not found.
I tried without the pipe so it would just print everything. Unfortunately it prints nothing.
I assume it is not opening my sorted file and this is why my final file is empty after my sed. If it's the case, then why won't awk read it?
In my script, I am using variables to define my directories and files (with the correct path). I know my issue is not about find my files or directories since they are perfectly defined at the beginning and used throughout the script. I tried to write the whole path instead of a variable and I get the same results.
for ID_FILES in `ls Infiles_dir/*.txt`
Simplify this to
for ID_FILES in Infiles_dir/*.txt
ls lists the files you pass it (except when you pass it directories, then it lists their content). Rather than telling it to display a list of files and parse the output, use the list of files you already have! This is more reliable (parsing the output of ls will fail if the file names contain whitespace or wildcard characters), clearer and faster. Don't parse the output of ls.
SORT_JOB=`echo "sort -m -n perl_files_dir/*.txt >>sorted_file.txt" | qsub -j oe -W depend=afterany$JOB_ID_ARRAY`
You'd make your life simpler if you used the right form of quoting in the right place. Don't use backquotes, because it's difficult to know how to quote things inside. Use $(…) instead, it's exactly equivalent except that it is parsed in a sane way.
I recommend using a here document for the shell snippet that you're feeding to qsub. You have fewer quoting issues to worry about, and it's more readable.
While we're at it, always put double quotes around variable substitutions and command substitutions: "$some_variable", "$(some_command)". Annoyingly, $var in shell syntax doesn't mean “take the value of the variable var”, it means “take the value of the variable var, parse it as a list of wildcard patterns, and replace each pattern by the list of matching files if there are matching files”. This extra stuff is turned off if the substitution happens inside double quotes (or in a here document, by the way): "$var" means “take the value of the variable var”.
SORT_JOB=$(qsub -j oe -W depend="afterany$JOB_ID_ARRAY" <<'EOF'
sort -m -n perl_files_dir/*.txt >>sorted_file.txt
EOF
)
We now get to the snippet where the quoting was actually causing a problem.
SED=`echo "awk '{\$2="";\$3="";\$4="";\$5="";\$6=""; print \$0}' sorted_file.txt \
| sed 's/ //g' >final_file.txt" | qsub -j oe -W depend=afterany$SORT_ARRAY`
The string that becomes the argument to the echo command is:
awk '{$2=;$3=;$4=;$5=;$6=; print $0}' sorted_file.txt | sed 's/ //g' >final_file.txt
This is syntactically incorrect, and that's why you're not getting any output.
You didn't escape the double quotes inside what was meant to be the awk snippet. It's a lot clearer if you use a here document. Also, you don't need the SED= part. You added it because you had a command substitution (a command between …), which substitutes the output of a command. But since you aren't interested in the output of the qsub command, don't take its output, just execute it.
qsub -j oe -W depend="afterany$SORT_ARRAY" <<'EOF'
awk '{$2="";$3="";$4="";$5="";$6=""; print $0}' sorted_file.txt |
sed 's/ //g' >final_file.txt
EOF
I'm not familiar with qsub, but presumably there's a way to get the error output and the return status of the commands it runs. Inspect that error output, you should have seen the errors from awk.
The version of awk that I am using, does not like the character escapes
awk --version
GNU Awk 3.1.7
spuder#cent64$ awk '{\$2="";\$3="";\$4=""; print \$0}' foo.txt
awk: {\$2="";\$3="";\$4=""; print \$0}
awk: ^ backslash not last character on line
Try the following syntax
awk '{for(i=2;i<=7;i++) $i="";print}' foo.txt
As a side note, if you are using Torque 4.x you may not be able to use a comma separated list of jobs with -W depend=, instead you may need to create a new PBS declarative (-W) for each job.
eg...
#Invalid syntax in newer versions of torque
qsub -W depend=foo,bar
Resources
backslash in gawk fields
Print all but the first three columns
http://docs.adaptivecomputing.com/torque/help.htm#topics/commands/qsub.htm#-W
I have been through the sed one liners but am still having trouble with my goal. I want to substitue matching strings on all but the first occurrence of a line. My exact usage would be:
$ echo 'cd /Users/joeuser/bump bonding/initial trials' | sed <<MAGIC HAPPENS>
cd /Users/joeuser/bump\ bonding/initial\ trials
The line replaced the space in bump bonding with the slash space bump\ bonding so that I can execute this line (since when the spaces aren't escaped I wouldn't be able to cd to it).
Update: I solved this by just using single quotes and outputting
cd 'blah blah/thing/another space/'
and then using source to execute the command. But it didn't answer my question. I'm still curious though... how would you use sed to fix it?
s/ /\\ /2g
The 2 specifies that the second one should apply, and the g specifies that all the rest should apply too. (This probably only works on GNU sed. According to the Open Group Base Specification, "If both g and n are specified, the results are unspecified.")
You can avoid the problem with g and n
Replace all of them, then undo the first one:
sed -e 's/ /\\ /g' -e 's/\\ / /1'
Here's another method which uses the t branch-if-substituted command:
sed ':a;s/\([^ ]* .*[^\\]\) \(.*\)/\1\\ \2/;ta'
which has the advantage of leaving existing backslash-space sequences in the input intact.
use awk
$ echo cd 'blah blah/thing/another space/' | awk '{for(i=2;i<NF;i++) $i=$i"\\"}1'
cd blah\ blah/thing/another\ space/
$ echo 'cd /Users/joeuser/bump bonding/initial trials' | awk '{for(i=2;i<NF;i++) $i=$i"\\"}1'
cd /Users/joeuser/bump\ bonding/initial\ trials
How can I make sed filter matching lines according to some expression, but ignore non-matching lines, instead of letting them print?
As a real example, I want to run scalac (the Scala compiler) on a set of files, and read from its -verbose output the .class files created. scalac -verbose outputs a bunch of messages, but we're only interested in those of the form [wrote some-class-name.class].
What I'm currently doing is this (|& is bash 4.0's way to pipe stderr to the next program):
$ scalac -verbose some-file.scala ... |& sed 's/^\[wrote \(.*\.class\)\]$/\1/'
This will extract the file names from the messages we're interested in, but will also let all other messages pass through unchanged! Of course we could do instead this:
$ scalac -verbose some-file.scala ... |& grep '^\[wrote .*\.class\]$' |
sed 's/^\[wrote \(.*\.class\)\]$/\1/'
which works but looks very much like going around the real problem, which is how to instruct sed to ignore non-matching lines from the input. So how do we do that?
If you don't want to print lines that don't match, you can use the combination of
-n option which tells sed not to print
p flag which tells sed to print what is matched
This gives:
sed -n 's/.../.../p'
Another way with plain sed:
sed -e 's/.../.../;t;d'
s/// is a substituion, t without any label conditionally skips all following commands, d deletes line.
No need for perl or grep.
(edited after Nicholas Riley's suggestion)
Rapsey raised a relevant point about multiple substitutions expressions.
First, quoting an Unix SE answer, you can "prefix most sed commands with an address to limit the lines to which they apply".
Second, you can group commands within curly braces {} (separated with a semi-colon ; or a new line)
Third, add the print flag p on the last substitution
Syntax:
sed -n -e '/^given_regexp/ {s/regexp1/replacement1/flags1;[...];s/regexp1/replacement1/flagsnp}'
Example (see Here document for more details):
Code:
sed -n -e '/^ha/ {s/h/k/g;s/a/e/gp}' <<SAMPLE
haha
hihi
SAMPLE
Result:
keke
sed -n '/.../!p'
There is no need for a substitution.