The procedure Indent indents a string s by replacing the beginning of each line in s by lineindent spaces, if lineindent is a non-negative integer, or if lineindent is a string by that string.

The indented string is returned.

The lineindent argument is optional. It is equal to $8$ by default, which causes the input text to be indented by $8$ spaces.

All of the StringTools package commands treat strings as (null-terminated) sequences of $8$-bit (ASCII) characters.  Thus, there is no support for multibyte character encodings, such as unicode encodings.

$\mathrm{with}\left(\mathrm{StringTools}\right)\:$

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(''a\backslash nb\backslash nc''\right)\right)$

        a
        b
        c

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(''a\backslash nb\backslash nc''\,2\right)\right)$

  a
  b
  c

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(''a\backslash nb\backslash nc''\,''-''\right)\right)$

 - a
 - b
 - c

$\mathrm{txt}≔''Arma\; virumque\; cano,\; Troiae\; qui\; primus\; ab\; oris\backslash nItaliam,\; fato\; profugus,\; Laviniaque\; venit\backslash nlitora,\; multum\; ille\; et\; terris\; iactatus\; et\; alto\backslash nvi\; superum\; saevae\; memorem\; Iunonis\; ob\; iram;\backslash nmulta\; quoque\; et\; bello\; passus,\; dum\; conderet\; urbem,\backslash ninferretque\; deos\; Latio,\; genus\; unde\; Latinum,\backslash nAlbanique\; patres,\; atque\; altae\; moenia\; Romae.''\:$

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{txt}\right)$

Arma virumque cano, Troiae qui primus ab oris
Italiam, fato profugus, Laviniaque venit
litora, multum ille et terris iactatus et alto
vi superum saevae memorem Iunonis ob iram;
multa quoque et bello passus, dum conderet urbem,
inferretque deos Latio, genus unde Latinum,
Albanique patres, atque altae moenia Romae.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{txt}\right)\right)$

        Arma virumque cano, Troiae qui primus ab oris
        Italiam, fato profugus, Laviniaque venit
        litora, multum ille et terris iactatus et alto
        vi superum saevae memorem Iunonis ob iram;
        multa quoque et bello passus, dum conderet urbem,
        inferretque deos Latio, genus unde Latinum,
        Albanique patres, atque altae moenia Romae.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{txt}\,2\right)\right)$

  Arma virumque cano, Troiae qui primus ab oris
  Italiam, fato profugus, Laviniaque venit
  litora, multum ille et terris iactatus et alto
  vi superum saevae memorem Iunonis ob iram;
  multa quoque et bello passus, dum conderet urbem,
  inferretque deos Latio, genus unde Latinum,
  Albanique patres, atque altae moenia Romae.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{txt}\,''--''\right)\right)$

--Arma virumque cano, Troiae qui primus ab oris
--Italiam, fato profugus, Laviniaque venit
--litora, multum ille et terris iactatus et alto
--vi superum saevae memorem Iunonis ob iram;
--multa quoque et bello passus, dum conderet urbem,
--inferretque deos Latio, genus unde Latinum,
--Albanique patres, atque altae moenia Romae.

$\mathrm{pandp}≔''It\; is\; a\; truth\; universally\; acknowledged,\; that\; a\; single\; man\; in\backslash npossession\; of\; a\; good\; fortune,\; must\; be\; in\; want\; of\; a\; wife.\backslash n\backslash nHowever\; little\; known\; the\; feelings\; or\; views\; of\; such\; a\; man\; may\backslash nbe\; on\; his\; first\; entering\; a\; neighbourhood,\; this\; truth\; is\; so\; well\backslash nfixed\; in\; the\; minds\; of\; the\; surrounding\; families,\; that\; he\; is\; considered\backslash nthe\; rightful\; property\; of\; some\; one\; or\; other\; of\; their\; daughters.''\:$

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{pandp}\right)$

It is a truth universally acknowledged, that a single man in
possession of a good fortune, must be in want of a wife.

However little known the feelings or views of such a man may
be on his first entering a neighbourhood, this truth is so well
fixed in the minds of the surrounding families, that he is considered
the rightful property of some one or other of their daughters.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{pandp}\right)\right)$

        It is a truth universally acknowledged, that a single man in
        possession of a good fortune, must be in want of a wife.
        
        However little known the feelings or views of such a man may
        be on his first entering a neighbourhood, this truth is so well
        fixed in the minds of the surrounding families, that he is considered
        the rightful property of some one or other of their daughters.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{pandp}\,2\right)\right)$

  It is a truth universally acknowledged, that a single man in
  possession of a good fortune, must be in want of a wife.
  
  However little known the feelings or views of such a man may
  be on his first entering a neighbourhood, this truth is so well
  fixed in the minds of the surrounding families, that he is considered
  the rightful property of some one or other of their daughters.

$\mathrm{randj}≔''Two\; households,\; both\; alike\; in\; dignity,\backslash nIn\; fair\; Verona,\; where\; we\; lay\; our\; scene,\backslash nFrom\; ancient\; grudge\; break\; to\; new\; mutiny,\backslash nWhere\; civil\; blood\; makes\; civil\; hands\; unclean.\backslash nFrom\; forth\; the\; fatal\; loins\; of\; these\; two\; foes\backslash nA\; pair\; of\; star-cross\text{'}d\; lovers\; take\; their\; life;\backslash nWhose\; misadventur\text{'}d\; piteous\; overthrows\backslash nDoth\; with\; their\; death\; bury\; their\; parents\text{'}\; strife.\backslash nThe\; fearful\; passage\; of\; their\; death-mark\text{'}d\; love,\backslash nAnd\; the\; continuance\; of\; their\; parents\text{'}\; rage,\backslash nWhich,\; but\; their\; children\text{'}s\; end,\; naught\; could\; remove,\backslash nIs\; now\; the\; two\; hours\text{'}\; traffic\; of\; our\; stage;\backslash nThe\; which\; if\; you\; with\; patient\; ears\; attend,\backslash nWhat\; here\; shall\; miss,\; our\; toil\; shall\; strive\; to\; mend.''\:$

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{randj}\right)$

Two households, both alike in dignity,
In fair Verona, where we lay our scene,
From ancient grudge break to new mutiny,
Where civil blood makes civil hands unclean.
From forth the fatal loins of these two foes
A pair of star-cross'd lovers take their life;
Whose misadventur'd piteous overthrows
Doth with their death bury their parents' strife.
The fearful passage of their death-mark'd love,
And the continuance of their parents' rage,
Which, but their children's end, naught could remove,
Is now the two hours' traffic of our stage;
The which if you with patient ears attend,
What here shall miss, our toil shall strive to mend.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{randj}\,''''\right)\right)$

  Two households, both alike in dignity,
  In fair Verona, where we lay our scene,
  From ancient grudge break to new mutiny,
  Where civil blood makes civil hands unclean.
  From forth the fatal loins of these two foes
  A pair of star-cross'd lovers take their life;
  Whose misadventur'd piteous overthrows
  Doth with their death bury their parents' strife.
  The fearful passage of their death-mark'd love,
  And the continuance of their parents' rage,
  Which, but their children's end, naught could remove,
  Is now the two hours' traffic of our stage;
  The which if you with patient ears attend,
  What here shall miss, our toil shall strive to mend.

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{randj}\,2\right)\right)$

  Two households, both alike in dignity,
  In fair Verona, where we lay our scene,
  From ancient grudge break to new mutiny,
  Where civil blood makes civil hands unclean.
  From forth the fatal loins of these two foes
  A pair of star-cross'd lovers take their life;
  Whose misadventur'd piteous overthrows
  Doth with their death bury their parents' strife.
  The fearful passage of their death-mark'd love,
  And the continuance of their parents' rage,
  Which, but their children's end, naught could remove,
  Is now the two hours' traffic of our stage;
  The which if you with patient ears attend,
  What here shall miss, our toil shall strive to mend.

$\mathrm{txt}≔''first\backslash nsecond\backslash nthird''\:$

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{txt}\right)$

first
second
third

$\mathrm{printf}\left(''\%s\backslash n''\,\mathrm{Indent}\left(\mathrm{txt}\,''-''\right)\right)$

 - first
 - second
 - third