Removing the first space in a line

Question

How can I remove only the first space from a line like the one below without removing the other spaces in the same line?

Example Input:

2015-04-18 10:21:59 10 05430 -9999 -9999 000000000000

Example Output:

2015-04-1810:21:59 10 05430 -9999 -9999 000000000000

Answer 1

You may use sed for this:

sed 's/ //' infile >outfile

This applies a substitution to all lines of the file infile that will substitute the first space character with nothing (i.e. remove it). The output is stored in the file outfile. With sed 's/ //N', where N is an integer between 1 and 9, you can pick which space to remove.

If the line is in a shell variable, you could use

var="${var/ /}"

This uses the ${parameter/pattern/string} parameter expansion in bash to do the same thing as the sed command, but on the value in $var. The resulting string is, in this example, then stored back into $var.

Answer 2

Using awk:

> awk '{print $1$2,$3,$4,$5,$6,$7}' yourfile > outputfile

The output:

> cat outputfile

2015-04-1810:21:59 10 05430 -9999 -9999 000000000000

You can remove any space in the line and keep any one

Assuming: Input file must contain:

1. no leading whitespace
2. no consecutive spaces
3. no tabs
4. less than seven spaces total

If any of this assumption are violated, the result will not be correct

Answer 3

You can use Vim in Ex mode:

ex -sc '%s/ //|x' file

1. % select all lines

2. s substitute

3. x save and close

Answer 4

Small and simple Perl one-liner:

$ perl -ane 'printf "%s",@F[0];@F[0]="";print @F'  <<< "2015-04-18 10:21:59 10 05430 -9999 -9999 000000000000"                        
2015-04-1810:21:591005430-9999-9999000000000000

Or even simpler as suggested by mik in comments:

perl -pe 's/ //' <<< "2015-04-18 10:21:59 10 05430 -9999 -9999 000000000000"

Python can do it too. Here's a small script that does the job. It can be reduced to a one-liner, if necessary:

#!/usr/bin/env python
from __future__ import print_function
import sys
for line in sys.stdin:
    words=line.strip().split()
    print(words[0],end="")
    print(" ".join(words[1:]))

And with the same line in input file duplicated 3 times, here's a test for multi-line input:

$ ./remove_leading_space.py < input.txt                                                                                               
2015-04-1810:21:59 10 05430 -9999 -9999 000000000000
2015-04-1810:21:59 10 05430 -9999 -9999 000000000000
2015-04-1810:21:59 10 05430 -9999 -9999 000000000000

If you just one single line edited, you can do it like so:

$ ./remove_leading_space.py <<< "2015-04-18 10:21:59 10 05430 -9999 -9999 000000000000"                                               

Answer 5

It's a quite simple question.

sed -i 's/ //' /path/to/file

Try this command and don't add s in the end of sed expression.

It will just remove the first space each line.