tsort.1 (1467B)
1 .Dd 2016-02-16 2 .Dt TSORT 1 3 .Os sbase 4 .Sh NAME 5 .Nm tsort 6 .Nd topological sort 7 .Sh SYNOPSIS 8 .Nm 9 .Op Ar file 10 .Sh DESCRIPTION 11 .Nm 12 topologically sorts a graph. The graph is read 13 either from 14 .Ar file 15 or from standard input. The result is not optimized 16 for any particular usage. Loops are detected and 17 reported to standard error, but does not stop the sort. 18 .Pp 19 The input is a list of edges (vertex pairs), where 20 the edge is directed from the first vertex to the 21 second vertex. 22 .Sh OPTIONS 23 None. 24 .Sh EXIT STATUS 25 .Bl -tag -width Ds 26 .It 0 27 The graph as successfully sorted. 28 .It 1 29 The graph as successfully sorted, but contained loops. 30 .It > 1 31 An error occurred. 32 .El 33 .Sh EXAMPLES 34 .Bd -literal -offset left 35 The input 36 37 a a 38 a b 39 a c 40 a c 41 a d 42 b c 43 c b 44 e f 45 46 or equivalently 47 48 a a a b a c a c a d 49 b c c b e f 50 51 represents the graph 52 53 ┌─┐ 54 ↓ │ 55 ┏━━━┓ 56 ┌──────┃ a ┃──────┐ 57 │ ┗━━━┛ │ 58 │ │ │ │ 59 ↓ ↓ ↓ ↓ 60 ┏━━━┓───→┏━━━┓ ┏━━━┓ 61 ┃ b ┃ ┃ c ┃ ┃ d ┃ 62 ┗━━━┛←───┗━━━┛ ┗━━━┛ 63 64 ┏━━━┓ ┏━━━┓ 65 ┃ e ┃───→┃ f ┃ 66 ┗━━━┛ ┗━━━┛ 67 .Ed 68 .Sh STANDARDS 69 The 70 .Nm 71 utility is compliant with the 72 .St -p1003.1-2013 73 specification.