How to set width of longtable

Question

I have a longtable defined like this

\documentclass[a4paper,12pt]{report}

\usepackage{longtable} 

\begin{document}
\setlength\LTleft{0pt} 
\begin{longtable}[l]{ lllllllllllllllll }
00000576 & 576 & 577 & 578 & 579 & 580 & 581 & 582 & 583 & 584 & 585 & 586 & 587 & 588 & 589 & 590 & 591 \\ 
00000592 & 592 & 593 & 594 & 595 & 596 & 597 & 598 & 599 & 600 & 601 & 602 & 603 & 604 & 605 & 606 & 607 \\ 
00000608 & 608 & 609 & 610 & 611 & 612 & 613 & 614 & 615 & 616 & 617 & 618 & 619 & 620 & 621 & 622 & 623 \\ 
00000624 & 624 & 625 & 626 & 627 & 628 & 629 & 630 & 631 & 632 & 633 & 634 & 635 & 636 & 637 & 638 & 639 \\ 
00000640 & 640 & 641 & 642 & 643 & 644 & 645 & 646 & 647 & 648 & 649 & 650 & 651 & 652 & 653 & 654 & 655 \\ 
00000656 & 656 & 657 & 658 & 659 & 660 & 661 & 662 & 663 & 664 & 665 & 666 & 667 & 668 & 669 & 670 & 671 \\ 
00000672 & 672 & 673 & 674 & 675 & 676 & 677 & 678 & 679 & 680 & 681 & 682 & 683 & 684 & 685 & 686 & 687 \\ 
00000688 & 688 & 689 & 690 & 691 & 692 & 693 & 694 & 695 & 696 & 697 & 698 & 699 & 700 & 701 & 702 & 703 \\ 
00000704 & 704 & 705 & 706 & 707 & 708 & 709 & 710 & 711 & 712 & 713 & 714 & 715 & 716 & 717 & 718 & 719 \\ 
00000720 & 720 & 721 & 722 & 723 & 724 & 725 & 726 & 727 & 728 & 729 & 730 & 731 & 732 & 733 & 734 & 735 \\ 
00000736 & 736 & 737 & 738 & 739 & 740 & 741 & 742 & 743 & 744 & 745 & 746 & 747 & 748 & 749 & 750 & 751 \\ 
00000752 & 752 & 753 & 754 & 755 & 756 & 757 & 758 & 759 & 760 & 761 & 762 & 763 & 764 & 765 & 766 & 767 \\ 
00000768 & 768 & 769 & 770 & 771 & 772 & 773 & 774 & 775 & 776 & 777 & 778 & 779 & 780 & 781 & 782 & 783 \\ 
00000784 & 784 & 785 & 786 & 787 & 788 & 789 & 790 & 791 & 792 & 793 & 794 & 795 & 796 & 797 & 798 & 799 \\ 
00000800 & 800 & 801 & 802 & 803 & 804 & 805 & 806 & 807 & 808 & 809 & 810 & 811 & 812 & 813 & 814 & 815 \\ 
00000816 & 816 & 817 & 818 & 819 & 820 & 821 & 822 & 823 & 824 & 825 & 826 & 827 & 828 & 829 & 830 & 831 \\ 
00000832 & 832 & 833 & 834 & 835 & 836 & 837 & 838 & 839 & 840 & 841 & 842 & 843 & 844 & 845 & 846 & 847 \\ 
00000848 & 848 & 849 & 850 & 851 & 852 & 853 & 854 & 855 & 856 & 857 & 858 & 859 & 860 & 861 & 862 & 863 \\ 
00000864 & 864 & 865 & 866 & 867 & 868 & 869 & 870 & 871 & 872 & 873 & 874 & 875 & 876 & 877 & 878 & 879 \\ 
00000880 & 880 & 881 & 882 & 883 & 884 & 885 & 886 & 887 & 888 & 889 & 890 & 891 & 892 & 893 & 894 & 895 \\ 
00000896 & 896 & 897 & 898 & 899 & 900 & 901 & 902 & 903 & 904 & 905 & 906 & 907 & 908 & 909 & 910 & 911 \\ 
00000912 & 912 & 913 & 914 & 915 & 916 & 917 & 918 & 919 & 920 & 921 & 922 & 923 & 924 & 925 & 926 & 927 \\ 
00000928 & 928 & 929 & 930 & 931 & 932 & 933 & 934 & 935 & 936 & 937 & 938 & 939 & 940 & 941 & 942 & 943 \\ 
00000944 & 944 & 945 & 946 & 947 & 948 & 949 & 950 & 951 & 952 & 953 & 954 & 955 & 956 & 957 & 958 & 959 \\ 
00000960 & 960 & 961 & 962 & 963 & 964 & 965 & 966 & 967 & 968 & 969 & 970 & 971 & 972 & 973 & 974 & 975 \\ 
00000976 & 976 & 977 & 978 & 979 & 980 & 981 & 982 & 983 & 984 & 985 & 986 & 987 & 988 & 989 & 990 & 991 \\
\end{longtable}

\end{document}

This table extends very close to the end of the right side of the page. How can I set the width of such a table?

Answer 1

You can set the widths of columns using p{2cm} as for a normal tabular. With longtable you don't explicitly set the total table width but you can set the left and right margin to set the width as shown in the longtable documentation

% Normally centring is the default, but this document specifies
% \DescribeMacro{\LTright}
%\begin{verbatim}
% \setlength\LTleft\parindent
% \setlength\LTright\fill
%\end{verbatim}
% in the preamble,
%  which means that the tables are set flush left, but
% indented by the usual paragraph indentation. Any lengths can be
% specified for these two parameters, but at least one of them should be
% a rubber length so that it fills up the width of the page, unless
% rubber lengths are added between the columns using the
% "\extracolsep" command.
% For instance
%\begin{verbatim}
%  \begin{tabular*}{\textwidth}{@{\extracolsep{...}}...}
%\end{verbatim}
% produces a full width table, to get a similar effect with
% \env{longtable} specify
%\begin{verbatim}
% \setlength\LTleft{0pt}
% \setlength\LTright{0pt}
% \begin{longtable}{@{\extracolsep{...}}...}
%\end{verbatim}
%

For your table I think you either need to make the font smaller or set it landscape so either

\begin{document}
\small
\setlength\tabcolsep{2pt}
\begin{longtable}[l]{ lllllllllllllllll }

or get the lscape package and

\begin{document}
\begin{landscape}
\begin{longtable}[l]{ lllllllllllllllll }
...
\end{longtable}
\end{landscape}

Or, if you don't want your document margins to be used as margins, you can steal the space from there:

\begin{document}
\setlength\LTleft{-1in}
\setlength\LTright{-1in plus 1 fill}
\begin{longtable}{ lllllllllllllllll }