1*48593Scael.\" Copyright (c) 1989, 1991 The Regents of the University of California. 241960Smarc.\" All rights reserved. 341960Smarc.\" 448326Sbostic.\" %sccs.include.redist.roff% 541960Smarc.\" 6*48593Scael.\" @(#)vis.1 5.2 (Berkeley) 04/23/91 741960Smarc.\" 8*48593Scael.Dd 9*48593Scael.Dt VIS 1 10*48593Scael.Os 11*48593Scael.Sh NAME 12*48593Scael.Nm vis 13*48593Scael.Nd display non-printable characters in a visual format 14*48593Scael.Sh SYNOPSIS 15*48593Scael.Nm vis 16*48593Scael.Op Fl cbflnostw 17*48593Scael.Op Fl F Ar foldwidth 18*48593Scael.Op Ar file ... 19*48593Scael.Sh DESCRIPTION 20*48593Scael.Nm Vis 21*48593Scaelis a filter for converting non-printable characters 22*48593Scaelinto a visual representation. It differs from 23*48593Scael.Ql cat -v 24*48593Scaelin that 2544589Smarcthe form is unique and invertible. By default, all non-graphic 2644589Smarccharacters except space, tab, and newline are encoded. 2744589SmarcA detailed description of the 28*48593Scaelvarious visual formats is given in 29*48593Scael.Xr vis 3 . 30*48593Scael.Pp 31*48593ScaelOptions supported by 32*48593Scael.Nm vis : 33*48593Scael.Bl -tag -width Ds 34*48593Scael.It Fl b 35*48593ScaelTurns off prepending of backslash before up-arrow control sequences 36*48593Scaeland meta characters, and disables the doubling of backslashes. This 37*48593Scaelproduces output which is neither invertible or precise, but does 38*48593Scaelrepresent a minimum of change to the input. It is similar to 39*48593Scael.Dq Li cat -v . 40*48593Scael.It Fl c 4141960SmarcRequest a format which displays a small subset of the 4241960Smarcnon-printable characters using C-style backslash sequences. 43*48593Scael.It Fl F 4441960SmarcCauses 45*48593Scael.Nm vis 46*48593Scaelto fold output lines to foldwidth columns (default 80), like 47*48593Scael.Xr fold 1 , 48*48593Scaelexcept 4944589Smarcthat a hidden newline sequence is used, (which is removed 50*48593Scaelwhen inverting the file back to its original form with 51*48593Scael.Xr unvis 1 ) . 5241960SmarcIf the last character in the encoded file does not end in a newline, 5344589Smarca hidden newline sequence is appended to the output. 5444589SmarcThis makes 5544589Smarcthe output usuable with various editors and other utilities which 5644589Smarctypically don't work with partial lines. 57*48593Scael.It Fl f 58*48593ScaelSame as 59*48593Scael.Fl F . 60*48593Scael.It Fl l 61*48593ScaelMark newlines with the visable sequence 62*48593Scael.Ql \e$ , 63*48593Scaelfollowed by the newline. 64*48593Scael.It Fl n 6544589SmarcTurns off any encoding, except for the fact that backslashes are 66*48593Scaelstill doubled and hidden newline sequences inserted if 67*48593Scael.Fl f 68*48593Scaelor 69*48593Scael.Fl F 70*48593Scaelis selected. When combined with the 71*48593Scael.Fl f 72*48593Scaelflag, 73*48593Scael.Nm vis 74*48593Scaelbecomes like 75*48593Scaelan invertible version of the 76*48593Scael.Xr fold 1 77*48593Scaelutility. That is, the output 78*48593Scaelcan be unfolded by running the output through 79*48593Scael.It Fl o 80*48593ScaelRequest a format which displays non-printable characters as 81*48593Scaelan octal number, \eddd. 82*48593Scael.It Fl s 83*48593ScaelOnly characters considered unsafe to send to a terminal are encoded. 84*48593ScaelThis flag allows backspace, bell, and carriage return in addition 85*48593Scaelto the default space, tab and newline. 86*48593Scael.Xr unvis 1 . 87*48593Scael.It Fl t 88*48593ScaelTabs are also encoded. 89*48593Scael.It Fl w 90*48593ScaelWhite space (space-tab-newline) is also encoded. 91*48593Scael.El 92*48593Scael.Sh SEE ALSO 93*48593Scael.Xr unvis 1 94*48593Scael.Xr vis 3 95*48593Scael.Sh HISTORY 96*48593ScaelThe 97*48593Scael.Nm 98*48593Scaelcommand is 99*48593Scael.Ud . 100