1bfs(1) User Commands bfs(1)
2
6 bfs - big file scanner
7
9 /usr/bin/bfs [-] filename
10
13 The bfs command is (almost) like ed(1) except that it is read-only and
14 processes much larger files. Files can be up to 1024K bytes and 32K
15 lines, with up to 512 characters, including new-line, per line (255 for
16 16-bit machines). bfs is usually more efficient than ed(1) for scanning
17 a file, since the file is not copied to a buffer. It is most useful for
18 identifying sections of a large file where csplit(1) can be used to
19 divide it into more manageable pieces for editing.
20 Normally, the size of the file being scanned is printed, as is the size
23 of any file written with the w (write) command. The optional − sup‐
24 presses printing of sizes. Input is prompted with * if P and a carriage
25 return are typed, as in ed(1). Prompting can be turned off again by
26 inputting another P and carriage return. Note that messages are given
27 in response to errors if prompting is turned on.
28 All address expressions described under ed(1) are supported. In addi‐
31 tion, regular expressions may be surrounded with two symbols besides /
32 and ?:
33 > indicates downward search without wrap-around, and
35 < indicates upward search without wrap-around.
38 There is a slight difference in mark names; that is, only the letters a
42 through z may be used, and all 26 marks are remembered.
43 bfs Commands
45 The e, g, v, k, p, q, w, =, !, and null commands operate as described
46 under ed(1). Commands such as −−−, +++−, +++=, −12, and +4p are
47 accepted. Note that 1,10p and 1,10 will both print the first ten
48 lines. The f command only prints the name of the file being scanned;
49 there is no remembered file name. The w command is independent of
50 output diversion, truncation, or crunching (see the xo, xt, and xc com‐
51 mands, below). The following additional commands are available:
52 xf file
54 Further commands are taken from the named file. When an end-of-file
56 is reached, an interrupt signal is received or an error occurs,
57 reading resumes with the file containing the xf. The xf commands
58 may be nested to a depth of 10.
59 xn
62 List the marks currently in use (marks are set by the k command).
64 xo [file]
67 Further output from the p and null commands is diverted to the
69 named file, which, if necessary, is created mode 666 (readable and
70 writable by everyone), unless your umask setting (see umask(1))
71 dictates otherwise. If file is missing, output is diverted to the
72 standard output. Note that each diversion causes truncation or cre‐
73 ation of the file.
74 : label
77 This positions a label in a command file. The label is terminated
79 by new-line, and blanks between the : (colon) and the start of the
80 label are ignored. This command may also be used to insert comments
81 into a command file, since labels need not be referenced.
82 ( . , . )xb/regular expression/label
85 A jump (either upward or downward) is made to label if the command
87 succeeds. It fails under any of the following conditions:
88 1. Either address is not between 1 and $.
90 2. The second address is less than the first.
92 3. The regular expression does not match at least one line
94 in the specified range, including the first and last
95 lines.
96 On success, . (dot) is set to the line matched and a jump is made
97 to label. This command is the only one that does not issue an error
98 message on bad addresses, so it may be used to test whether
99 addresses are bad before other commands are executed. Note that the
100 command, xb/^/ label, is an unconditional jump.
101 The xb command is allowed only if it is read from someplace other
103 than a terminal. If it is read from a pipe, only a downward jump is
104 possible.
105 xt number
108 Output from the p and null commands is truncated to, at most, num‐
110 ber characters. The initial number is 255.
111 xv[digit][spaces][value]
114 The variable name is the specified digit following the xv. The com‐
116 mands xv5100 or xv5 100 both assign the value 100 to the variable
117 5. The command xv61,100p assigns the value 1,100p to the variable
118 6. To reference a variable, put a % in front of the variable name.
119 For example, using the above assignments for variables 5 and 6:
120 1,%5p
122 1,%5
123 %6
124 will all print the first 100 lines.
127 g/%5/p
129 would globally search for the characters 100 and print each line
131 containing a match. To escape the special meaning of %, a \ must
132 precede it.
133 g/".*\%[cds]/p
135 could be used to match and list %c, %d, or %s formats (for example,
137 "printf"-like statements) of characters, decimal integers, or
138 strings. Another feature of the xv command is that the first line
139 of output from a UNIX system command can be stored into a variable.
140 The only requirement is that the first character of value be an !.
141 For example:
142 .w junk
144 xv5!cat junk
145 !rm junk
146 !echo "%5"
147 xv6!expr %6 + 1
148 would put the current line into variable 35, print it, and incre‐
151 ment the variable 36 by one. To escape the special meaning of ! as
152 the first character of value, precede it with a \.
153 xv7\!date
155 stores the value !date into variable 7.
157 xbz label
160 xbn label
161 These two commands will test the last saved return code from the
163 execution of a UNIX system command (!command) or nonzero value,
164 respectively, to the specified label. The two examples below both
165 search for the next five lines containing the string size:
166 Example 1:
168 xv55
169 : l
170 /size/
171 xv5!expr %5 − 1
172 !if 0%5 != 0 exit 2
173 xbn l
174 Example 2:
179 xv45
180 : l
181 /size/
182 xv4!expr %4 − 1
183 !if 0%4 = 0 exit 2
184 xbz l
185 xc [switch]
191 If switch is 1, output from the p and null commands is crunched; if
193 switch is 0, it is not. Without an argument, xc reverses switch.
194 Initially, switch is set for no crunching. Crunched output has
195 strings of tabs and blanks reduced to one blank and blank lines
196 suppressed.
197
200 The following operand is supported:
201 filename Any file up to 1024K bytes and 32K lines, with up to 512
203 characters, including new-line, per line (255 for 16-bit
204 machines). filename can be a section of a larger file which
205 has been divided into more manageable sections for editing
206 by the use of csplit(1).
207
210 The following exit values are returned:
211 0 Successful completion without any file or command errors.
213 >0 An error occurred.
216
219 See attributes(5) for descriptions of the following attributes:
220 ┌─────────────────────────────┬─────────────────────────────┐
225 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
226 ├─────────────────────────────┼─────────────────────────────┤
227 │Availability │SUNWesu │
228 └─────────────────────────────┴─────────────────────────────┘
229
231 csplit(1), ed(1), umask(1), attributes(5)
232
234 Message is ? for errors in commands, if prompting is turned off. Self-
235 explanatory error messages are displayed when prompting is on.
236SunOS 5.11 20 May 1996 bfs(1)