1MED(1NCARG) NCAR GRAPHICS MED(1NCARG)
2
6 med - NCAR CGM metafile frame editor
7
9 med [ -e command ]* [ -f sfilename ] [ -l local_dir ] [ -V ] [ file‐
10 name]
11
13 med is a frame-level, metafile editor designed to resemble syntacti‐
14 cally UNIX's sed(1) and ed(1). med operates on a copy of filename,
15 called a buffer, and overwrites a file only when you issue the w
16 (write) command. med provides line oriented editing commands to dis‐
17 play or delete frames from the buffer, to move, copy or merge frames
18 within the buffer, or to write frames from and read frames into the
19 buffer. By default med reads in commands from standard input.
20
22 -e command
23 command is a single med command. The valid med commands are dis‐
24 cussed in the Commands section below. Multiple -e options may
25 appear on a single command line. Be careful to use quotes if
26 your command contains spaces or metacharacters that might be
27 interpreted by the shell. When this option is used med does not
28 enter interactive mode. It simply performs the given commands
29 and then exits.
30 -f sfilename
32 Execute the med line-separated list of commands in the file
33 sfilename. After the commands are exhausted med will exit.
34 -l local_dir
36 Use local_dir as the tmp directory for scratch disk space. If
37 this option is not specified med will use the value of the
38 $NCARG_TMP or the $TMPDIR environment variable. See ncargin‐
39 tro(1ncarg) for a discussion on NCAR Graphics environment vari‐
40 ables.
41 -V Print the version number and then exit.
43
45 Command Structure
46 med commands attempt to have a syntactically identical form to those of
47 ed(1) or sed(1). Commands consist of an optional address or two
48 optional, comma separated, addresses, followed by a command, which may
49 be abbreviated, possibly followed by a third address or a command spe‐
50 cific argument list :
51 [ address [, address ] ] command [ address | args ]
53If only one address is specified, operations are performed on that frame. If
55two addresses are specified, med performs the operation on the inclusive range
56of frames. If no address is specified then the current frame is used as a
57default. The exception to this are the w (write) and the a (append) commands.
58The default address for w is the entire buffer.
59For example, 1,10p means “print (display) frame 1 through 10” (two addresses),
62as default), and 1,5c5 means “append a copy of frames 1 through 5 at frame 5”
63(three addresses). The meaning of argument varies for each operation. In
65command for instance, argument is the name of the file to write to.
66Unlike its friends ed(1) and sed(1) med attempts to be fairly user friendly.
68If an invalid or ambiguous command is given med will tell you so. If med
69thinks it recognizes a command with invalid arguments a usage statement for
70the offending command is given. If a particular command fails and med is smart
71enough to figure out why it will tell you. med will almost ALWAYS immediately
72terminate when an error occurs while processing commands from a file or the
73command line. Help is available by using the h command. Usage statements for a
74particular command may be obtained with: h command name .
75 Addresses
77 Frames can be addressed in several ways:
78 nnn By frame number. Frames in the buffer are numbered relative to
80 the start of the buffer. The first frame is frame 1.
81 $ The last frame of the buffer.
83 . The current frame. med keeps track of the frame on which you
85 last performed an operation. This frame is called the current
86 frame. You can address this frame by typing a “dot” character.
87 ±n By relative frame number. Address the frame number that is n
89 frames higher, or n frames lower than the current frame.
90 address±n
92 An address followed by a plus sign (+) or a minus sign (-), fol‐
93 lowed by a decimal number, specifies that address plus or minus
94 the indicated number of frames. If the address is omitted, the
95 current frame is used as the base. For example, `31-3'
96 addresses frame 28 in the buffer.
97 If you do not specify an address for a command to operate on, a command
99 that requires an address supplies one by default, usually the current
100 frame.
101 A pair of addresses separated by a comma signifies an inclusive range
103 of frames, and the current frame is not changed unless the command
104 changes it.
105 Commands
107 Only one command may appear per line. Commands may accept zero, one or
108 two addresses, followed by possibly a third address or an argument.
109 Commands that accept up to two addresses regard a third as an error.
110 Likewise, commands that do not accept an argument regard one as an
111 error. Commands may be abbreviated.
112 In the absence of a second address for a two or three address command
114 the command will regard the second address as the same as the first.
115 For example, 2d is equivalent to 2,2d . The absence of a first
116 address, where required, will result in the current frame being used as
117 the default. The same is true in the absence of a required third
118 address. For example, c is equivalent to .,.c..
119 The commands q (quit) and e (edit) may be followed by a '!' to override
121 med's user protection.
122 In the following list of med commands, the default addresses/arguments
124 appear in parentheses; the parenthesized addresses are not part of the
125 command. Unless otherwise noted a command does not change the current
126 frame number.
127 (1,$)append metafile
129 Append buffer to a file. Append the addressed frames in the buf‐
130 fer to metafile. If no address is specified the entire buffer
131 is written. If the file does not exist create it.
132 (.,.) copy (.)
133 Copy frames. Duplicate the addressed frames in the buffer and
134 append them after the third address. The current frame becomes
135 the destination of the last frame copied.
136 (.,.)delete
137 Delete the addressed lines from the buffer. delete accepts one
138 or two addresses; the default is the current frame. The current
139 frame is set to the first frame after the deleted frame(s).
140 edit metafile
141 Edit a metafile. The current contents of the buffer, if any,
142 are erased. The named metafile is read in to the buffer. The
143 resulting current frame is the last frame in the buffer. If
144 changes have been made to the buffer since the last write med
145 will refuse the request unless the command is appended with a
146 '!'. edit prints the number of frames in the metafile. If no
147 metafile is given, the current metafile, if any is used. The
148 current frame becomes the last frame in the file.
149 help command
150 help. Give a usage message for command . If no command is
151 given, print list of command names with a short description of
152 each.
153 (.,.)label string
154 Label the addressed frames with string . The CGM Begin Picture
155 element contained in each metafile frame allows for the encoding
156 of character data. label provides a means for accessing this
157 data.
158 (.,.)merge
159 Merge the contents of the second addressed frame on top of the
160 first addressed frame. The first addressed frame is thus
161 changed. The second frame remains the same. The current frame is
162 set to the first addressed frame.
163 (.,.) move (.)
164 Move the addressed frames to the first frame following the third
165 address.
166 (.,.)print
167 Show the contents of the buffer at the given address. What is
168 actually displayed is information regarding the addressed
169 frames. This information includes: relative frame number within
170 the buffer, the number of records contained in the frame, the
171 starting record for the frame and the contents of the CGM ele‐
172 ment BEGIN PICTURE . If no address is specified the current
173 frame does not change. Otherwise it becomes the last frame
174 printed.
175 quit
176 Quit. Terminate the editing session without saving the buffer
177 contents. In order to save the buffer an explicit write must be
178 performed. If changes to the buffer have been made since the
179 last write med will refuse to terminate unless quit is appended
180 with a '!'.
181 (.)read metafile
182 Read in a metafile. Read the contents of metafile into the buf‐
183 fer and append it at the given address. metafile must be a
184 valid NCAR CGM. The resulting current frame is the last frame
185 read in.
186 (1,$)split<number> outfile
187 Split the current metafile into number files. The split command
188 attempts to create number metafiles from the addressed frames,
189 each containing approximately n / number frames where 'n' is the
190 total number of addressed frames. The first file is named out‐
191 file001.ncgm, the second file is named outfile002.ncgm, and so
192 on lexicographically. If no outfile is given, med is used as the
193 default (output files will be called med001.ncgm, med002.ncgm,
194 etc.).
195 (1,$)write metafile
196 Write buffer. Write the addressed frames in the buffer to
197 metafile. If no address is specified the entire buffer is writ‐
198 ten. If the file does not exist create it. If no file name is
199 specified med uses the last currently remembered file name, if
200 any. The currently remembered file name is the file name from
201 the most recent edit command, or the file name med was invoked
202 with if no edit commands have been issued.
203 ! command
204 Escape to the shell and execute command. command is a valid
205 UNIX command.
207 NCARG_TMP
208 If set, this environment variable contains a directory path to
209 be used for temporary files. On most systems the default is
210 /tmp.
212 /tmp/cgm_tools.# temporary; # is the process id.
213
215 To concatenate the files ncgm1, ncgm2, and ncgm3 into a single file
216 ncgm123 one might use the following:
217 % med -e 'r ncgm1' -e 'r ncgm2' -e 'r ncgm3' -e 'w ncgm123'
219 Or one could pass the following script to med as a -fscriptfile option
221 or enter the commands interactively.
222 r ncgm1
224 r ncgm2
225 r ncgm3
226 w ncgm123
227 To Overlay the contents of frame 5 on top of frame 4 from a file ncgm1
229 one could execute:
230 % med -e '4,5 me' -e 'w!' ncgm1
231
233 cgm(5NCARG), [22med(1), sed(1V)
234 Hardcopy: NCAR Graphics Fundamentals, UNIX Version
237 med
238 does not understand filenames that begin with a digit or a period.
239
241 The append, read and merge commands may produce surprising results. A
242 CGM may contain a set of global graphical primitive attributes that are
243 applied to every frame in a file. Thus reading frames in from a file
244 with different global attributes than the current working file may not
245 produce the desired effect. The same is true when appending frames to a
246 previously existing file. Similarly, the CGM standard specifies that
247 graphical attributes specified within a metafile frame affect all suc‐
248 ceeding primitives. Thus a frame which is the product of the merge com‐
249 mand may appear differently than expected.
251 Copyright (C) 1987-2009
252 University Corporation for Atmospheric Research
253 The use of this Software is governed by a License Agreement.
255NCARG January 1993 MED(1NCARG)