I tried gedit, nano, vi, leafpad and other text editors , it won't open, I tried cat and other file looking commands, and I ensure you it's a file not a directory!
This type of approach has a lot of misunderstanding because using - as an argument refers to STDIN/STDOUT i.e dev/stdin or dev/stdout .So if you want to open this type of file you have to specify the full location of the file such as ./- .For eg. , if you want to see what is in that file use cat ./-
Both cat < - and ./- command will give you the output
you can use redirection
cat < -file_name
It looks like the rev command doesn't treat - as a special character.
From the man page
The rev utility copies the specified files to standard output, reversing the order of characters in every line.
so
rev - | rev
should show what's in the file in the correct order.
I tried with pico or vi command.pico readme which allowed me open in editor and read the contents.
if you want to open this type of file you have to specify the full location of the file such as ./- .For eg. , if you want to see what is in that file use cat ./-
cat ./- is the syntax that reveals the correct password for bandit the "rev -" reveals something else
Related
I'm currently using the Linux command line and was just wondering whether there is a quick command you can enter into the console to open any of a given directory.
I'll give you an example of what I mean.
say in a directory ligands/
we have:
ligand_1993324
ligand_1993444
ligand 1993255
shoe_lace
water_bottle
Lets just say there are 100000 of these very similar directories. Because I'm lazy I just want to pick any random one of these, but it has to begin with ligand_199 for example.
Please not I'm trawled through the manual and can't find anything, I've also looked at other stacks, any help would be great!
There are a couple of versions of a program called variously "randomline" or "randline" about. This version shows its age (it's in Perl).
#!/usr/bin/perl
while(<>)
{
push #lines, $_;
}
$randline = $#lines;
$randline = rand($randline);
print $lines[$randline];
Given this in a file ~/bin/randomline, then your task reduces to the following, assuming that you want to open the file with vim:
vim $(ls ligands/ligand_199* | ~/bin/randomline)
You can use following:
files=(/my/dir/*)
file=`printf "%s\n" "${files[RANDOM % ${#files[#]}]}"`
cat file
Maybe something like
number=$(((RANDOM%10000)+1)) && emacs -nw "ligand_199$number" ?
I have received a csv file from a ftp server which I am ingesting into a table.
While ingesting the file I am receiving the error "File was a truncated file"
The actual reason is the data in a file contains $ and ^M$ in end of the line.
e.g :
ACT_RUN_TM, PROG_RUN_TM, US_HE_DT*^M$*
"CONFIRMED","","3600"$
How can I remove these $ and ^M$ from end of the line using linux command.
The ultimately correct solution is to transfer the file from the FTP server in text mode rather than binary mode, which does the appropriate end-of-line conversion for you. Change your download scripts or FTP application configuration to enable text transfers to fix this in future.
Assuming this is a one-shot transfer and you have already downloaded the file and just want to fix it, you can use tr(1) to translate characters. So to remove all control-M characters from a file, you can pipe through tr -d '\r'. Or if you want to replace them with control-J instead – for example you would do this if the file came from a pre-OSX Mac system — do tr '\r' '\n'.
It's odd to see ^M as not-the-last character, but:
sed -e 's/^M*\$$//g' <badfile >goodfile
Or use "sed -i" to update in-place.
(Note that "^M" is entered on the command line by pressing CTRL-V CTRL_M).
Update: It's been established that the question is wrong as the "^M$" are not in the file but displayed with VI. He actually wants to change CRLF pairs to just LF.
sed -e 's/^M$//g' <badfile >goodfile
I like to compare two text files and save the difference under linux.
I know there are tools like kdiff, diff vimdiff etc. but my expectation are as follows.
Output should be in a separate file
The difference should be quoted with colours, ex: delete line in red and added line in green something like that
It should ignore space differences
It should be an opensource tool
use tkdiff4 -w file-name1 file-name2
It fulfills all your requirements. Specific color might be an issue.
try colordiff and man diff for options for ignoring whitespace etc
Like,
#!/bin/bash
wdiff -w "\e[31m" -x "\e[0m" -y "\e[32m" -z "\e[0m" "$#";
replace \e by, well, the ASCII character with value 0x1A. Put the two commands into some file, and run it using redirection.
Save the changes to a file:
diff -Nur originalfile newfile > patchfile
Use the difference file to change the origin file:
patch originfile patchfile
I think this is the easiest way to save the changes and reload the changes.
By the way, you can use this command the create an update-package.
I have this file in a directory say test.php whose contents are below
< ? php $XZKsyG=’as’;
I want to pick up the file test.php with a search based on its content. So from the directory containing it I do:
grep 'php \$[a-zA-Z]*=.as.;'
However I get no result...what am I doing wrong?
Thanks
It works for me:
$ cat file
< ? php $XZKsyG=’as’;
$ grep 'php \$[a-zA-Z]*=.as.;' file
< ? php $XZKsyG=’as’;
Are you sure the contents of the file are exactly what you showed us?
Try cat -A file or od -c file to see whether the file really looks the way you think it does.
(Note that you don't need to escape the $ character; it's only a metacharacter at the end of a line. But escaping it should be ok.)
EDIT :
The characters around the as in your file are not ASCII apostrophes; they're Unicode RIGHT SINGLE QUOTATION MARK characters (0x2019). If the file is stored in UTF-8, each of them is represented as a 3-byte sequence. The grep command works for me because my locale settings "en_US.UTF-8" are such that a UTF-8 character is matched by . in a regexp, even if it has a multi-byte representation. I suspect your locale is such that it would be matched by ....
Probably the simplest solution is to edit the file to use ASCII apostrophes.
You might also want to play around with your locale settings. Try the grep command with $LANG set to "en_US.UTF-8".
What's the output of the locale command?
That works fine for me, though you may want to look into those "funny" single quotes you have around as:
pax$ cat testfile
< ? php $XZKsyG='as';
pax$ grep 'php \$[a-zA-Z]*=.as.;' testfile
< ? php $XZKsyG='as';
Failing that, there's some things you can look at. Some of these may sound silly but I'm really just checking all bases.
Are you sure the file contains only what you think it does? Executing od -xcb file will give you a hex dump of it for better checking.
Are you sure you're accessing the right file, in the right directory?
Have you done something silly like aliasing grep to be something else?
That's if you're looking for a file containing that string. If instead you're looking for a file named like that, you can use something like:
ls -1 | grep 'php \$[a-zA-Z]*=.as.;'
The ls -1 command gives you one file per line, and piping that through grep will filter out those not matching the pattern.
I suppose I should mention that I'm not really a big fan of file names with spaces in them, but I'm violently opposed to file names made up of PHP scripts :-)
diff -w command is used to create a side by side comparison diff file (instead of parallel)
i then view them using vi via ssh terminal
the changes are indicated by either "<" or "|" or ">"
Since the file i am viewing is a source code, navigating to changes alone
using above symbols is difficult since they are also in C source code.
How can i change these default symbols to desired ones ?
Kindly help. Thanks.
Instead of viewing the output of diff -w in vim, you can use vim's built-in diff:
vim -d file1 file2
This opens vim in a vertical split with both files open, and diff markings in the code. This is what it looks like:
And it works in a terminal too:
You can find a short tutorial here
According to my version of diff (2.8.1 from the GNU diffutils by the FSF) -w is used to change the width of the output; The -y parameter outputs side by side comparison. In combination, the two show no further effect than the -y parameter used alone, which means you may have an alias in your terminal profile or in the global terminal profile that aliases diff to diff -y.
I say all this because all options to change the symbols ("<", "|", and ">") conflict with the -y option. If you can live without side-by-side, you have the option of two other included output styles or defining your own. The two output styles are -c (context) and -u (unified). (For more information on what they do see the diff Wikipedia page. For more information on the options see the diff man page.)
A more in depth fix would be to use the following options:
diff --old-group-format="(deleted)---" \
--new-group-format="(added)---" \
--changed-group-format="(updated)---" \
--unchanged-group-format="(nodiff)---" \
old_file.c new_file.c
Now the old file's lines that are not present in the new file are represented by (deleted)---
The new file's lines that are not present in the old file are represented by (added)---
Lines that have been changed are represented by (updated)---
Lines common to both files are represented by (nodiff)---
Since you seem to do this often enough, you have the option of making it an alias in your terminal profile or writing a small shell script to handle it. For more options, see the manual's section on options and specifically see the section on line group formats for information on what you can put between the quotes in the format definitions.
Of course, if you must have side-by-side, try Nathan Fellman's idea above. Otherwise, there's the option of using a dedicated GUI tool for it such as Kompare.