1*62427Sbostic.\" Copyright (c) 1989, 1991, 1993 2*62427Sbostic.\" The Regents of the University of California. All rights reserved. 341960Smarc.\" 448326Sbostic.\" %sccs.include.redist.roff% 541960Smarc.\" 6*62427Sbostic.\" @(#)vis.1 8.1 (Berkeley) 06/06/93 741960Smarc.\" 848593Scael.Dd 948593Scael.Dt VIS 1 1058795Scael.Os BSD 4.4 1148593Scael.Sh NAME 1248593Scael.Nm vis 1348593Scael.Nd display non-printable characters in a visual format 1448593Scael.Sh SYNOPSIS 1548593Scael.Nm vis 1648593Scael.Op Fl cbflnostw 1748593Scael.Op Fl F Ar foldwidth 1848593Scael.Op Ar file ... 1948593Scael.Sh DESCRIPTION 2048593Scael.Nm Vis 2148593Scaelis a filter for converting non-printable characters 2248593Scaelinto a visual representation. It differs from 2348593Scael.Ql cat -v 2448593Scaelin 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 2848593Scaelvarious visual formats is given in 2948593Scael.Xr vis 3 . 3048593Scael.Pp 3148593ScaelOptions supported by 3248593Scael.Nm vis : 3348593Scael.Bl -tag -width Ds 3448593Scael.It Fl b 3548593ScaelTurns off prepending of backslash before up-arrow control sequences 3648593Scaeland meta characters, and disables the doubling of backslashes. This 3748593Scaelproduces output which is neither invertible or precise, but does 3848593Scaelrepresent a minimum of change to the input. It is similar to 3948593Scael.Dq Li cat -v . 4048593Scael.It Fl c 4141960SmarcRequest a format which displays a small subset of the 4241960Smarcnon-printable characters using C-style backslash sequences. 4348593Scael.It Fl F 4441960SmarcCauses 4548593Scael.Nm vis 4648593Scaelto fold output lines to foldwidth columns (default 80), like 4748593Scael.Xr fold 1 , 4848593Scaelexcept 4944589Smarcthat a hidden newline sequence is used, (which is removed 5048593Scaelwhen inverting the file back to its original form with 5148593Scael.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. 5748593Scael.It Fl f 5848593ScaelSame as 5948593Scael.Fl F . 6048593Scael.It Fl l 6148593ScaelMark newlines with the visable sequence 6248593Scael.Ql \e$ , 6348593Scaelfollowed by the newline. 6448593Scael.It Fl n 6544589SmarcTurns off any encoding, except for the fact that backslashes are 6648593Scaelstill doubled and hidden newline sequences inserted if 6748593Scael.Fl f 6848593Scaelor 6948593Scael.Fl F 7048593Scaelis selected. When combined with the 7148593Scael.Fl f 7248593Scaelflag, 7348593Scael.Nm vis 7448593Scaelbecomes like 7548593Scaelan invertible version of the 7648593Scael.Xr fold 1 7748593Scaelutility. That is, the output 7848593Scaelcan be unfolded by running the output through 7948593Scael.It Fl o 8048593ScaelRequest a format which displays non-printable characters as 8148593Scaelan octal number, \eddd. 8248593Scael.It Fl s 8348593ScaelOnly characters considered unsafe to send to a terminal are encoded. 8448593ScaelThis flag allows backspace, bell, and carriage return in addition 8548593Scaelto the default space, tab and newline. 8648593Scael.Xr unvis 1 . 8748593Scael.It Fl t 8848593ScaelTabs are also encoded. 8948593Scael.It Fl w 9048593ScaelWhite space (space-tab-newline) is also encoded. 9148593Scael.El 9248593Scael.Sh SEE ALSO 9348593Scael.Xr unvis 1 9448593Scael.Xr vis 3 9548593Scael.Sh HISTORY 9648593ScaelThe 9748593Scael.Nm 9858795Scaelcommand appears in 9958795Scael.Bx 4.4 . 100