Can we use Math mode in TeX using the Command Prompt?

Question

I would like to know whether math mode in TeX, could be used, through the command line, and if so, would the document compile? I don't know the steps to follow to accomplish it, through the prompt in the terminal. By the way, the operating system that I'm using, is Windows. If anyone can help me, I'll be greatly indebted!

Answer 1

The TeX engine doesn't care whether its input comes from a text file, or from direct entry at the terminal. Nor does it care whether it is invoked from the command line or by pressing a button in an IDE.

[Ians-MacBook-Pro:~/tex/stackexchange] ianthompson% pdflatex
This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014) (preloaded format=pdflatex)
 restricted \write18 enabled.
**\documentclass{article}
entering extended mode
LaTeX2e <2014/05/01>
Babel <3.9k> and hyphenation patterns for 78 languages loaded.

*\begin{document}
(/usr/local/texlive/2014/texmf-dist/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/local/texlive/2014/texmf-dist/tex/latex/base/size10.clo))
No file texput.aux.
*\[
*a = b 
*\]
*\end{document}
[1{/usr/local/texlive/2014/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./texput.aux)</usr/local/texlive/2014/texmf-dist/fonts/type1/public/amsfonts/c
m/cmmi10.pfb></usr/local/texlive/2014/texmf-dist/fonts/type1/public/amsfonts/cm
/cmr10.pfb>
Output written on texput.pdf (1 page, 15787 bytes).
Transcript written on texput.log.

So the answer is yes (whatever platform you use).

Answer 2

this is the transcript of a "successful" attempt to test the \theta command using command line input. observe that in order to get a system prompt, it's necessary to enter a complete document if using latex.

> latex
This is pdfTeX, Version 3.1415926-2.4-1.40.13 (TeX Live 2012)
**\documentclass{article}
entering extended mode
LaTeX2e <2011/06/27>
Babel <v3.8m> and hyphenation patterns for english, dumylang, nohyphenation, ge
rman-x-2012-05-30, ngerman-x-2012-05-30, afrikaans, ancientgreek, ibycus, arabi
c, armenian, basque, bulgarian, catalan, pinyin, coptic, croatian, czech, danis
h, dutch, ukenglish, usenglishmax, esperanto, estonian, ethiopic, farsi, finnis
h, french, friulan, galician, german, ngerman, swissgerman, monogreek, greek, h
ungarian, icelandic, assamese, bengali, gujarati, hindi, kannada, malayalam, ma
rathi, oriya, panjabi, tamil, telugu, indonesian, interlingua, irish, italian, 
kurmanji, latin, latvian, lithuanian, mongolian, mongolianlmc, bokmal, nynorsk,
 polish, portuguese, romanian, romansh, russian, sanskrit, serbian, serbianc, s
lovak, slovenian, spanish, swedish, turkish, turkmen, ukrainian, uppersorbian, 
welsh, loaded.

*\begin{document}
(/ams/texmf/archive/texlive2012/texmf-dist/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/ams/texmf/archive/texlive2012/texmf-dist/tex/latex/base/size10.clo))
(./texput.aux)
*$\theta$

*\end{document}
[1] (./texput.aux)
Output written on texput.dvi (1 page, 260 bytes).
Transcript written on texput.log.
>

here is the equivalent transcript using plain tex:

> tex
This is TeX, Version 3.1415926 (TeX Live 2012)
**\relax

*$\theta$

*\bye
[1]
Output written on texput.dvi (1 page, 252 bytes).
Transcript written on texput.log.
>

the plain tex version is also a complete document, ended with \bye. it's possible to interrupt either tex or latex with a ctrl-c at the * prompt, but you still need to enter something after an

*! Interruption.
<*> 

?

the proper response to that is x to terminate.

really, unless you're an absolutely flawless typist, it's easier to keep a little template around that can be used to test.