A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
-bash/zsh: calc command not found #Debian apt-get install apcalc #Ubuntu apt-get install apcalc #Arch Linux pacman -S calc #Kali Linux apt-get install apcalc #Fedora dnf install calc #OS X brew install calc #Raspbian apt-get install apcalc
calc 命令，是一个任意精度的计算器。
calc [-c] [-C] [-d]
[-D calc_debug[:resource_debug[:user_debug]]]
[-e] [-h] [-i] [-m mode] [-O]
[-p] [-q] [-s] [-u] [-v] [[--] calc_cmd ...]
#!/usr/local/bin/calc [other_flags ...] -f
CALC OPTIONS
-c Continue reading command lines even after a scan/parse error has caused the
abandonment of a line. Note that this option only deals with scanning and parsing
of the calc language. It does not deal with execution or run-time errors.
For example:
calc read many_errors.cal
will cause calc to abort on the first syntax error, whereas:
calc -c read many_errors.cal
will cause calc to try to process each line being read despite the scan/parse
errors that it encounters.
By default, calc startup resource files are silently ignored if not found. This
flag will report missing startup resource files unless -d is also given.
-C Permit the execution of custom builtin functions. Without this flag, calling the
custom() builtin function will simply generate an error.
Use of this flag may cause calc to execute functions that are non-standard and that
are not portable. Custom builtin functions are disabled by default for this
reason.
-d Disable the printing of the opening title. The printing of resource file debug and
informational messages is also disabled as if config("resource_debug", 0) had been
executed.
For example:
calc "read qtime> qtime(2)"
will output something like:
qtime(utc_hr_offset) defined
It's nearly ten past six.
whereas:
calc -d "read qtime> qtime(2)"
will just say:
It's nearly ten past six.
This flag disables the reporting of missing calc startup resource files.
-D calc_debug[:resource_debug[:user_debug]]
Force the initial value of config("calc_debug"), config("resource_debug") and
config("user_debug").
The : separated strings are interpreted as signed 32 bit integers. After an
optional leading sign a leading zero indicates octal conversion, and a leading
``0x'' or ``0X'' hexadecimal conversion. Otherwise, decimal conversion is assumed.
By default, calc_debug is 0, resource_debug is 3 and user_debug is 0.
For more information use the following calc command:
help config
-e Ignore any environment variables on startup. The getenv() builtin will still
return values, however.
-f This flag is required when using calc in shell script mode. It must be at the end
of the initial #! line of the script.
This flag is normally only at the end of a calc shell script. If the first line of
an executable file begins #! followed by the absolute pathname of the calc program
and the flag -f as in:
#!/usr/bin/calc [other_flags ...] -f
the rest of the file will be processed in shell script mode. See SHELL SCRIPT MODE
section of this man page below for details.
The actual form of this flag is:
-f filename
On systems that treat an executable that begins with #! as a script, the path of
the executable is appended by the kernel as the final argument to the exec() system
call. This is why the -f flag at the very end of the #! line.
It is possible use -f filename on the command line:
calc [other_flags ...] -f filename
This will cause calc to process lines in filename in shell script mode.
Use of -f implies -s. In addition, -d and -p are implied if -i is not given.
-h Print a help message. This option implies -q. This is equivalent to the calc
command help help. The help facility is disabled unless the mode is 5 or 7. See
-m.
-i Become interactive if possible. This flag will cause calc to drop into interactive
mode after the calc_cmd arguments on the command line are evaluated. Without this
flag, calc will exit after they are evaluated.
For example:
calc 2+5
will print the value 7 and exit whereas:
calc -i 2+5
will print the value 7 and prompt the user for more calc commands.
-m mode
This flag sets the permission mode of calc. It controls the ability for calc to
open files and execute programs. Mode may be a number from 0 to 7.
The mode value is interpreted in a way similar to that of the chmod(1) octal mode:
0 do not open any file, do not execute progs
1 do not open any file
2 do not open files for reading, do not execute progs
3 do not open files for reading
4 do not open files for writing, do not execute progs
5 do not open files for writing
6 do not execute any program
7 allow everything (default mode)
If one wished to run calc from a privileged user, one might want to use -m 0 in an
effort to make calc somewhat more secure.
Mode bits for reading and writing apply only on an open. Files already open are
not effected. Thus if one wanted to use the -m 0 in an effort to make calc
somewhat more secure, but still wanted to read and write a specific file, one might
want to do in sh(1), ksh(1), bash(1)-like shells:
calc -m 0 3<>a.file
Files presented to calc in this way are opened in an unknown mode. Calc will
attempt to read or write them if directed.
If the mode disables opening of files for reading, then the startup resource files
are disabled as if -q was given. The reading of key bindings is also disabled when
the mode disables opening of files for reading.
-O Use the old classic defaults instead of the default configuration. This flag as
the same effect as executing config("all", "oldcfg") at startup time.
NOTE: Older versions of calc used -n to setup a modified form of the default calc
configuration. The -n flag currently does nothing. Use of the -n flag is now
deprecated and may be used for something else in the future.
-p Pipe processing is enabled by use of -p. For example:
calc -p "2^21701-1" | fizzbin
In pipe mode, calc does not prompt, does not print leading tabs and does not print
the initial header. The -p flag overrides -i.
-q Disable the reading of the startup scripts.
-s By default, all calc_cmd args are evaluated and executed. This flag will disable
their evaluation and instead make them available as strings for the argv() builtin
function.
-u Disable buffering of stdin and stdout.
-v Print the calc version number and exit.
-- The double dash indicates to calc that no more options follow. Thus calc will
ignore a later argument on the command line even if it starts with a dash. This is
useful when entering negative values on the command line as in:
calc -p -- -1 - -7
以交互方式启动 calc：
calc
calc 在非交互模式下执行计算：
calc -p '85 * (36 / 4)'