8. The –lines switch

latexindent.pl can operate on a selection of lines of the file using the –lines or -n switch.

The basic syntax is –lines MIN-MAX, so for example

latexindent.pl --lines 3-7 myfile.tex
latexindent.pl -n 3-7 myfile.tex

will only operate upon lines 3 to 7 in myfile.tex. All of the other lines will not be operated upon by latexindent.pl.

The options for the lines switch are:

  • line range, as in –lines 3-7

  • single line, as in –lines 5

  • multiple line ranges separated by commas, as in –lines 3-5,8-10

  • negated line ranges, as in –lines !3-5 which translates to –lines 1-2,6-N, where N is the number of lines in your file.

We demonstrate this feature, and the available variations in what follows. We will use the file in Listing 565.

Listing 565 myfile.tex
 1Before the environments
 2\begin{one}
 3	first block, first line
 4	first block, second line
 5	first block, third line
 6	\begin{two}
 7		second block, first line
 8		second block, second line
 9		second block, third line
10		second block, fourth line
11	\end{two}
12\end{one}
Example 148

We demonstrate the basic usage using the command

latexindent.pl --lines 3-7 myfile.tex -o=+-mod1

which instructs latexindent.pl to only operate on lines 3 to 7; the output is given in Listing 566.

Listing 566 myfile-mod1.tex
 1Before the environments
 2\begin{one}
 3first block, first line
 4first block, second line
 5first block, third line
 6\begin{two}
 7second block, first line
 8		second block, second line
 9		second block, third line
10		second block, fourth line
11	\end{two}
12\end{one}

The following two calls to latexindent.pl are equivalent

latexindent.pl --lines 3-7 myfile.tex -o=+-mod1
latexindent.pl --lines 7-3 myfile.tex -o=+-mod1

as latexindent.pl performs a check to put the lowest number first.

Example 149

You can call the lines switch with only one number and in which case only that line will be operated upon. For example

latexindent.pl --lines 5 myfile.tex -o=+-mod2

instructs latexindent.pl to only operate on line 5; the output is given in Listing 567.

Listing 567 myfile-mod2.tex
 1Before the environments
 2\begin{one}
 3	first block, first line
 4	first block, second line
 5first block, third line
 6	\begin{two}
 7		second block, first line
 8		second block, second line
 9		second block, third line
10		second block, fourth line
11	\end{two}
12\end{one}

The following two calls are equivalent:

latexindent.pl --lines 5 myfile.tex
latexindent.pl --lines 5-5 myfile.tex
Example 150

If you specify a value outside of the line range of the file then latexindent.pl will ignore the lines argument, detail as such in the log file, and proceed to operate on the entire file.

For example, in the following call

latexindent.pl --lines 11-13 myfile.tex

latexindent.pl will ignore the lines argument, and operate on the entire file because Listing 565 only has 12 lines.

Similarly, in the call

latexindent.pl --lines -1-3 myfile.tex

latexindent.pl will ignore the lines argument, and operate on the entire file because we assume that negatively numbered lines in a file do not exist.

Example 151

You can specify multiple line ranges as in the following

latexindent.pl --lines 3-5,8-10 myfile.tex -o=+-mod3

which instructs latexindent.pl to operate upon lines 3 to 5 and lines 8 to 10; the output is given in Listing 568.

Listing 568 myfile-mod3.tex
 1Before the environments
 2\begin{one}
 3first block, first line
 4first block, second line
 5first block, third line
 6	\begin{two}
 7		second block, first line
 8second block, second line
 9second block, third line
10second block, fourth line
11	\end{two}
12\end{one}

The following calls to latexindent.pl are all equivalent

latexindent.pl --lines 3-5,8-10 myfile.tex
latexindent.pl --lines 8-10,3-5 myfile.tex
latexindent.pl --lines 10-8,3-5 myfile.tex
latexindent.pl --lines 10-8,5-3 myfile.tex

as latexindent.pl performs a check to put the lowest line ranges first, and within each line range, it puts the lowest number first.

Example 152

There’s no limit to the number of line ranges that you can specify, they just need to be separated by commas. For example

latexindent.pl --lines 1-2,4-5,9-10,12 myfile.tex -o=+-mod4

has four line ranges: lines 1 to 2, lines 4 to 5, lines 9 to 10 and line 12. The output is given in Listing 569.

Listing 569 myfile-mod4.tex
 1Before the environments
 2\begin{one}
 3	first block, first line
 4	first block, second line
 5	first block, third line
 6	\begin{two}
 7		second block, first line
 8		second block, second line
 9	second block, third line
10	second block, fourth line
11	\end{two}
12\end{one}

As previously, the ordering does not matter, and the following calls to latexindent.pl are all equivalent

latexindent.pl --lines 1-2,4-5,9-10,12 myfile.tex
latexindent.pl --lines 2-1,4-5,9-10,12 myfile.tex
latexindent.pl --lines 4-5,1-2,9-10,12 myfile.tex
latexindent.pl --lines 12,4-5,1-2,9-10 myfile.tex

as latexindent.pl performs a check to put the lowest line ranges first, and within each line range, it puts the lowest number first.

Example 153

You can specify negated line ranges by using ! as in

latexindent.pl --lines !5-7 myfile.tex -o=+-mod5

which instructs latexindent.pl to operate upon all of the lines except lines 5 to 7.

In other words, latexindent.pl will operate on lines 1 to 4, and 8 to 12, so the following two calls are equivalent:

latexindent.pl --lines !5-7 myfile.tex
latexindent.pl --lines 1-4,8-12 myfile.tex

The output is given in Listing 570.

Listing 570 myfile-mod5.tex
 1Before the environments
 2\begin{one}
 3	first block, first line
 4	first block, second line
 5	first block, third line
 6	\begin{two}
 7		second block, first line
 8	second block, second line
 9	second block, third line
10	second block, fourth line
11	\end{two}
12\end{one}
Example 154

You can specify multiple negated line ranges such as

latexindent.pl --lines !5-7,!9-10 myfile.tex -o=+-mod6

which is equivalent to:

latexindent.pl --lines 1-4,8,11-12 myfile.tex -o=+-mod6

The output is given in Listing 571.

Listing 571 myfile-mod6.tex
 1Before the environments
 2\begin{one}
 3	first block, first line
 4	first block, second line
 5	first block, third line
 6	\begin{two}
 7		second block, first line
 8	second block, second line
 9		second block, third line
10		second block, fourth line
11	\end{two}
12\end{one}
Example 155

If you specify a line range with anything other than an integer, then latexindent.pl will ignore the lines argument, and operate on the entire file.

Sample calls that result in the lines argument being ignored include the following:

latexindent.pl --lines 1-x myfile.tex
latexindent.pl --lines !y-3 myfile.tex
Example 156

We can, of course, use the lines switch in combination with other switches.

For example, let’s use with the file in Listing 572.

Listing 572 myfile1.tex
1Before the environments
2\begin{one}
3	first block, first line
4	first block, second line
5	first block, third line
6	\begin{two} body \end{two}
7\end{one}

We can demonstrate interaction with the -m switch (see Section 6); in particular, if we use Listing 462, Listing 446 and Listing 447 and run

latexindent.pl --lines 6 myfile1.tex -o=+-mod1 -m -l env-mlb2,env-mlb7,env-mlb8 -o=+-mod1

then we receive the output in Listing 573.

Listing 573 myfile1-mod1.tex
1Before the environments
2\begin{one}
3	first block, first line
4	first block, second line
5	first block, third line
6\begin{two}
7	body
8\end{two}
9\end{one}