1BCAL(1) User Commands BCAL(1)
2
6 bcal - Storage expression calculator.
7
9 bcal [-c N] [-f loc] [-s bytes] [expr] [N [unit]] [-b [expr]] [-m] [-d]
10 [-h]
11
13 bcal (Byte CALculator) is a command-line utility to help with numerical
14 calculations and expressions involving binary prefixes, SI/IEC conver‐
15 sion, byte addressing, base conversion, LBA/CHS calculation etc.
16 It invokes GNU bc for non-storage expressions. Alternatively, it can
18 also invoke calc (http://www.isthe.com/chongo/tech/comp/calc/). To use
19 calc:
20 export BCAL_USE_CALC=1
22 bcal uses [SI and IEC binary prefixes]:
24 https://en.wikipedia.org/wiki/Binary_prefix
25
27 * evaluate arithmetic expressions involving storage units
28 * perform general purpose calculations (using bc or calc)
29 * works with piped input or file redirection
30 * convert to IEC/SI standard data storage units
31 * interactive mode with the last valid result stored for reuse
32 * show the address in bytes
33 * show address as LBA:OFFSET
34 * convert CHS to LBA and vice versa
35 * base conversion to binary, decimal and hex
36 * custom sector size, max heads/cylinder and max sectors/track
37 * minimal dependencies
38
40 1. Interactive mode: bcal enters the REPL mode if no arguments are
41 provided. Storage unit conversion, base conversion and expression
42 evaluation are supported in this mode. The last valid result is
43 stored in the variable r.
44 2. Expression: Expression passed as argument in one-shot mode must be
46 within double quotes. Inner spaces are ignored. Supported opera‐
47 tors: +, -, *, /, % and C bitwise operators (except ~ due to stor‐
48 age width dependency).
49 3. N [unit]: N can be a decimal or '0x' prefixed hex value. unit can
51 be B/KiB/MiB/GiB/TiB/kB/MB/GB/TB. Default is Byte. As all of these
52 tokens are unique, unit is case-insensitive.
53 4. Numeric representation: Decimal and hex are recognized in expres‐
55 sions and unit conversions. Binary is also recognized in other op‐
56 erations.
57 5. Syntax: Prefix hex inputs with '0x', binary inputs with '0b'.
59 6. Precision: 128 bits if __uint128_t is available or 64 bits for nu‐
61 merical conversions. Floating point operations use long double.
62 Negative values in storage expressions are unsupported. Only 64-bit
63 operating systems are supported.
64 7. Fractional bytes do not exist, because they can't be addressed.
66 bcal shows the floor value of non-integer bytes.
67 8. CHS and LBA syntax:
69 - LBA: 'lLBA-MAX_HEAD-MAX_SECTOR' [NOTE: LBA starts with 'l'
70 (case ignored)]
71 - CHS: 'cC-H-S-MAX_HEAD-MAX_SECTOR' [NOTE: CHS starts with 'c'
72 (case ignored)]
73 - Format conversion arguments must be hyphen separated.
74 - Any unspecified value, including the one preceding the first
75 '-' to the one following the last '-', is considered '0' (zero).
76 - Examples:
77 - 'c-50--0x12-' -> C = 0, H = 50, S = 0, MH = 0x12, MS = 0
78 - 'l50-0x12' -> LBA = 50, MH = 0x12, MS = 0
79 9. Default values:
81 - sector size: 0x200 (512)
82 - max heads per cylinder: 0x10 (16)
83 - max sectors per track: 0x3f (63)
84 10. bc variables: scale = 10, ibase = 10. r is synced and can be used
86 in expressions. bc is not called in minimal output mode. To use
87 calc instead of bc, export BCAL_USE_CALC=1.
88
90 -c=N Show decimal, binary and hex representation of positive integer
91 N.
92 -f=loc Convert CHS to LBA or LBA to CHS. loc is hyphen-separated repre‐
94 sentation of LBA or CHS. Please refer to the Operational Notes
95 section for more details.
96 -s=bytes
98 Sector size in bytes. Default value is 512.
99 -b=[expr]
101 Start in bc mode. If expression is provided, evaluate in bc and
102 quit.
103 -m Show minimal output (e.g. decimal bytes).
105 -d Enable debug information and logs.
107 -h Show program help, storage sizes on the system and exit.
109
111 b Toggle bc mode.
112 r Show result from last operation.
114 s Show sizes of storage types.
116 ? Show prompt help.
118 q, double Enter
120 Quit the program.
121
123 1. Evaluate arithmetic expression of storage units
124 $ bcal "(5kb+2mb)/3"
126 $ bcal "5 tb / 12"
127 $ bcal "2.5mb*3"
128 $ bcal "(2giB * 2) / (2kib >> 2)"
129 2. Convert storage capacity to other units and get address, LBA.
131 $ bcal 20140115 b
133 $ bcal 0x1335053 B
134 $ bcal 0xaabbcc kb
135 $ bcal 0xdef Gib
136 Note that the units are case-insensitive.
137 3. Convert storage capacity, set sector size to 4096 to calculate LBA.
139 $ bcal 0xaabbcc kb -s 4096
141 4. Convert LBA to CHS.
143 $ bcal -f l500
145 $ bcal -f l0x600-18-0x7e
146 $ bcal -f l0x300-0x12-0x7e
147 5. Convert CHS to LBA.
149 $ bcal -f c10-10-10
151 $ bcal -f c0x10-0x10-0x10
152 $ bcal -f c0x10-10-2-0x12
153 $ bcal -f c-10-2-0x12
154 $ bcal -f c0x10-10--0x12
155 6. Show binary, decimal and hex representations of a number.
157 $ bcal -c 20140115
159 $ bcal -c 0b1001100110101000001010011
160 $ bcal -c 0x1335053
161 bcal> c 20140115 // Interactive mode
162 7. Invoke bc.
164 $ bcal -b '3.5 * 2.1 + 5.7'
166 bcal> b // Interactive mode
167 bc vars: scale = 10, ibase = 10, last = r
168 bc> 3.5 * 2.1 + 5.7
169 8. Pipe input.
171 $ printf '15 kib + 15 gib \n r / 5' | bcal -m
173 $ printf '15 + 15 + 2' | bcal -bm
174 9. Redirect from file.
176 $ cat expr
178 15 gib + 15 kib
179 r / 5
180 $ bcal -m < expr
181 10. Use as a general-purpose calculator.
183 $ bcal -b
185
187 Arun Prakash Jana <engineerarun@gmail.com>
188
190 https://github.com/jarun/bcal
191
193 https://github.com/jarun/bcal/issues
194
196 Copyright © 2016 Arun Prakash Jana <engineerarun@gmail.com>
197 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/li‐
199 censes/gpl.html>.
200 This is free software: you are free to change and redistribute it.
201 There is NO WARRANTY, to the extent permitted by law.
202Version 2.4 24 Jan 2022 BCAL(1)