diff options
Diffstat (limited to 'manuals/bc/EN.1')
| -rw-r--r-- | manuals/bc/EN.1 | 111 |
1 files changed, 28 insertions, 83 deletions
diff --git a/manuals/bc/EN.1 b/manuals/bc/EN.1 index a972005515a6..99ccb822ea78 100644 --- a/manuals/bc/EN.1 +++ b/manuals/bc/EN.1 @@ -25,14 +25,12 @@ .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" -.TH "BC" "1" "February 2023" "Gavin D. Howard" "General Commands Manual" +.TH "BC" "1" "November 2023" "Gavin D. Howard" "General Commands Manual" .nh .ad l .SH NAME -.PP bc - arbitrary-precision decimal arithmetic language and calculator .SH SYNOPSIS -.PP \f[B]bc\f[R] [\f[B]-cCghilPqRsvVw\f[R]] [\f[B]--digit-clamp\f[R]] [\f[B]--no-digit-clamp\f[R]] [\f[B]--global-stacks\f[R]] [\f[B]--help\f[R]] [\f[B]--interactive\f[R]] [\f[B]--mathlib\f[R]] @@ -44,7 +42,6 @@ bc - arbitrary-precision decimal arithmetic language and calculator [\f[B]--file\f[R]=\f[I]file\f[R]\&...] [\f[I]file\f[R]\&...] .SH DESCRIPTION -.PP bc(1) is an interactive processor for a language first standardized in 1991 by POSIX. (See the \f[B]STANDARDS\f[R] section.) @@ -73,7 +70,6 @@ If parsing scripts meant for other bc(1) implementations still does not work, that is a bug and should be reported. See the \f[B]BUGS\f[R] section. .SH OPTIONS -.PP The following are the options that bc(1) accepts. .TP \f[B]-C\f[R], \f[B]--no-digit-clamp\f[R] @@ -174,19 +170,16 @@ without worrying that the change will affect other functions. Thus, a hypothetical function named \f[B]output(x,b)\f[R] that simply printed \f[B]x\f[R] in base \f[B]b\f[R] could be written like this: .IP -.nf -\f[C] +.EX define void output(x, b) { obase=b x } -\f[R] -.fi +.EE .PP instead of like this: .IP -.nf -\f[C] +.EX define void output(x, b) { auto c c=obase @@ -194,8 +187,7 @@ define void output(x, b) { x obase=c } -\f[R] -.fi +.EE .PP This makes writing functions much easier. .PP @@ -209,12 +201,10 @@ converter, it is possible to replace that capability with various shell aliases. Examples: .IP -.nf -\f[C] +.EX alias d2o=\[dq]bc -e ibase=A -e obase=8\[dq] alias h2b=\[dq]bc -e ibase=G -e obase=2\[dq] -\f[R] -.fi +.EE .PP Second, if the purpose of a function is to set \f[B]ibase\f[R], \f[B]obase\f[R], or \f[B]scale\f[R] globally for any other purpose, it @@ -441,7 +431,6 @@ This is a \f[B]non-portable extension\f[R]. .PP All long options are \f[B]non-portable extensions\f[R]. .SH STDIN -.PP If no files or expressions are given by the \f[B]-f\f[R], \f[B]--file\f[R], \f[B]-e\f[R], or \f[B]--expression\f[R] options, then bc(1) reads from \f[B]stdin\f[R]. @@ -458,7 +447,6 @@ Second, after an \f[B]if\f[R] statement, bc(1) doesn\[cq]t know if an \f[B]else\f[R] statement will follow, so it will not execute until it knows there will not be an \f[B]else\f[R] statement. .SH STDOUT -.PP Any non-error output is written to \f[B]stdout\f[R]. In addition, if history (see the \f[B]HISTORY\f[R] section) and the prompt (see the \f[B]TTY MODE\f[R] section) are enabled, both are output @@ -467,7 +455,7 @@ to \f[B]stdout\f[R]. \f[B]Note\f[R]: Unlike other bc(1) implementations, this bc(1) will issue a fatal error (see the \f[B]EXIT STATUS\f[R] section) if it cannot write to \f[B]stdout\f[R], so if \f[B]stdout\f[R] is closed, as in -\f[B]bc >&-\f[R], it will quit with an error. +\f[B]bc >&-\f[R], it will quit with an error. This is done so that bc(1) can report problems when \f[B]stdout\f[R] is redirected to a file. .PP @@ -475,13 +463,12 @@ If there are scripts that depend on the behavior of other bc(1) implementations, it is recommended that those scripts be changed to redirect \f[B]stdout\f[R] to \f[B]/dev/null\f[R]. .SH STDERR -.PP Any error output is written to \f[B]stderr\f[R]. .PP \f[B]Note\f[R]: Unlike other bc(1) implementations, this bc(1) will issue a fatal error (see the \f[B]EXIT STATUS\f[R] section) if it cannot write to \f[B]stderr\f[R], so if \f[B]stderr\f[R] is closed, as in -\f[B]bc 2>&-\f[R], it will quit with an error. +\f[B]bc 2>&-\f[R], it will quit with an error. This is done so that bc(1) can exit with an error code when \f[B]stderr\f[R] is redirected to a file. .PP @@ -489,7 +476,6 @@ If there are scripts that depend on the behavior of other bc(1) implementations, it is recommended that those scripts be changed to redirect \f[B]stderr\f[R] to \f[B]/dev/null\f[R]. .SH SYNTAX -.PP The syntax for bc(1) programs is mostly C-like, with some differences. This bc(1) follows the POSIX standard (see the \f[B]STANDARDS\f[R] section), which is a much more thorough resource for the language this @@ -568,7 +554,6 @@ These are \f[B]non-portable extensions\f[R]. .PP Either semicolons or newlines may separate statements. .SS Comments -.PP There are two kinds of comments: .IP "1." 3 Block comments are enclosed in \f[B]/*\f[R] and \f[B]*/\f[R]. @@ -577,7 +562,6 @@ Line comments go from \f[B]#\f[R] until, and not including, the next newline. This is a \f[B]non-portable extension\f[R]. .SS Named Expressions -.PP The following are named expressions in bc(1): .IP "1." 3 Variables: \f[B]I\f[R] @@ -606,7 +590,6 @@ Named expressions are required as the operand of of \f[B]assignment\f[R] operators (see the \f[I]Operators\f[R] subsection). .SS Operands -.PP The following are valid operands in bc(1): .IP " 1." 4 Numbers (see the \f[I]Numbers\f[R] subsection below). @@ -710,7 +693,6 @@ otherwise. See the \f[B]OPTIONS\f[R] section. This is a \f[B]non-portable extension\f[R]. .SS Numbers -.PP Numbers are strings made up of digits, uppercase letters, and at most \f[B]1\f[R] period for a radix. Numbers can have up to \f[B]BC_NUM_MAX\f[R] digits. @@ -758,7 +740,6 @@ and is meant to provide an easy way to set the current \f[B]ibase\f[R] If clamping is on, and the clamped value of a character is needed, use a leading zero, i.e., for \f[B]A\f[R], use \f[B]0A\f[R]. .SS Operators -.PP The following arithmetic and logical operators can be used. They are listed in order of decreasing precedence. Operators in the same group have the same precedence. @@ -848,9 +829,9 @@ The operators will be described in more detail below. .TP \f[B]++\f[R] \f[B]--\f[R] The prefix and postfix \f[B]increment\f[R] and \f[B]decrement\f[R] -operators behave exactly like they would in C. -They require a named expression (see the \f[I]Named Expressions\f[R] -subsection) as an operand. +operators behave exactly like they would in C. They require a named +expression (see the \f[I]Named Expressions\f[R] subsection) as an +operand. .RS .PP The prefix versions of these operators are more efficient; use them @@ -971,7 +952,6 @@ This is \f[I]not\f[R] a short-circuit operator. This is a \f[B]non-portable extension\f[R]. .RE .SS Statements -.PP The following items are statements: .IP " 1." 4 \f[B]E\f[R] @@ -1049,11 +1029,9 @@ occur before the \f[B]quit\f[R] statement before exiting. .PP In other words, for the bc(1) code below: .IP -.nf -\f[C] +.EX for (i = 0; i < 3; ++i) i; quit -\f[R] -.fi +.EE .PP Other bc(1) implementations will print nothing, and this bc(1) will print \f[B]0\f[R], \f[B]1\f[R], and \f[B]2\f[R] on successive lines @@ -1070,7 +1048,6 @@ command. .PP An expression by itself is evaluated and printed, followed by a newline. .SS Strings -.PP If strings appear as a statement by themselves, they are printed without a trailing newline. .PP @@ -1089,7 +1066,6 @@ resets (see the \f[B]RESET\f[R] section). Assigning strings to variables and array elements and passing them to functions are \f[B]non-portable extensions\f[R]. .SS Print Statement -.PP The \[lq]expressions\[rq] in a \f[B]print\f[R] statement may also be strings. If they are, there are backslash escape sequences that are interpreted @@ -1121,7 +1097,6 @@ character to be printed as-is. Any non-string expression in a print statement shall be assigned to \f[B]last\f[R], like any other expression that is printed. .SS Stream Statement -.PP The expressions in a \f[B]stream\f[R] statement may also be strings. .PP If a \f[B]stream\f[R] statement is given a string, it prints the string @@ -1135,17 +1110,14 @@ The result is then printed as though \f[B]obase\f[R] is \f[B]256\f[R] and each digit is interpreted as an 8-bit ASCII character, making it a byte stream. .SS Order of Evaluation -.PP All expressions in a statment are evaluated left to right, except as necessary to maintain order of operations. This means, for example, assuming that \f[B]i\f[R] is equal to \f[B]0\f[R], in the expression .IP -.nf -\f[C] +.EX a[i++] = i++ -\f[R] -.fi +.EE .PP the first (or 0th) element of \f[B]a\f[R] is set to \f[B]1\f[R], and \f[B]i\f[R] is equal to \f[B]2\f[R] at the end of the expression. @@ -1154,28 +1126,23 @@ This includes function arguments. Thus, assuming \f[B]i\f[R] is equal to \f[B]0\f[R], this means that in the expression .IP -.nf -\f[C] +.EX x(i++, i++) -\f[R] -.fi +.EE .PP the first argument passed to \f[B]x()\f[R] is \f[B]0\f[R], and the second argument is \f[B]1\f[R], while \f[B]i\f[R] is equal to \f[B]2\f[R] before the function starts executing. .SH FUNCTIONS -.PP Function definitions are as follows: .IP -.nf -\f[C] +.EX define I(I,...,I){ auto I,...,I S;...;S return(E) } -\f[R] -.fi +.EE .PP Any \f[B]I\f[R] in the parameter list or \f[B]auto\f[R] list may be replaced with \f[B]I[]\f[R] to make a parameter or \f[B]auto\f[R] var an @@ -1203,18 +1170,15 @@ equivalent to \f[B]return (0)\f[R], unless the function is a \f[B]void\f[R] function (see the \f[I]Void Functions\f[R] subsection below). .SS Void Functions -.PP Functions can also be \f[B]void\f[R] functions, defined as follows: .IP -.nf -\f[C] +.EX define void I(I,...,I){ auto I,...,I S;...;S return } -\f[R] -.fi +.EE .PP They can only be used as standalone expressions, where such an expression would be printed alone, except in a print statement. @@ -1230,15 +1194,12 @@ The word \[lq]void\[rq] is only treated specially right after the .PP This is a \f[B]non-portable extension\f[R]. .SS Array References -.PP For any array in the parameter list, if the array is declared in the form .IP -.nf -\f[C] +.EX *I[] -\f[R] -.fi +.EE .PP it is a \f[B]reference\f[R]. Any changes to the array in the function are reflected, when the @@ -1248,11 +1209,9 @@ Other than this, all function arguments are passed by value. .PP This is a \f[B]non-portable extension\f[R]. .SH LIBRARY -.PP All of the functions below are available when the \f[B]-l\f[R] or \f[B]--mathlib\f[R] command-line flags are given. .SS Standard Library -.PP The standard (see the \f[B]STANDARDS\f[R] section) defines the following functions for the math library: .TP @@ -1305,7 +1264,6 @@ This is a transcendental function (see the \f[I]Transcendental Functions\f[R] subsection below). .RE .SS Transcendental Functions -.PP All transcendental functions can return slightly inaccurate results, up to 1 ULP (https://en.wikipedia.org/wiki/Unit_in_the_last_place). This is unavoidable, and the article at @@ -1333,7 +1291,6 @@ The transcendental functions in the standard math library are: .IP \[bu] 2 \f[B]j(x, n)\f[R] .SH RESET -.PP When bc(1) encounters an error or a signal that it has a non-default handler for, it resets. This means that several things happen. @@ -1354,7 +1311,6 @@ Note that this reset behavior is different from the GNU bc(1), which attempts to start executing the statement right after the one that caused an error. .SH PERFORMANCE -.PP Most bc(1) implementations use \f[B]char\f[R] types to calculate the value of \f[B]1\f[R] decimal digit at a time, but that can be slow. This bc(1) does something different. @@ -1377,7 +1333,6 @@ checking. This integer type depends on the value of \f[B]BC_LONG_BIT\f[R], but is always at least twice as large as the integer type used to store digits. .SH LIMITS -.PP The following are the limits on bc(1): .TP \f[B]BC_LONG_BIT\f[R] @@ -1441,7 +1396,6 @@ large (at least on 64-bit machines) that there should not be any point at which they become a problem. In fact, memory should be exhausted before these limits should be hit. .SH ENVIRONMENT VARIABLES -.PP As \f[B]non-portable extensions\f[R], bc(1) recognizes the following environment variables: .TP @@ -1580,7 +1534,6 @@ This environment variable overrides the default, which can be queried with the \f[B]-h\f[R] or \f[B]--help\f[R] options. .RE .SH EXIT STATUS -.PP bc(1) returns the following exit statuses: .TP \f[B]0\f[R] @@ -1657,7 +1610,6 @@ These exit statuses allow bc(1) to be used in shell scripting with error checking, and its normal behavior can be forced by using the \f[B]-i\f[R] flag or \f[B]--interactive\f[R] option. .SH INTERACTIVE MODE -.PP Per the standard (see the \f[B]STANDARDS\f[R] section), bc(1) has an interactive mode and a non-interactive mode. Interactive mode is turned on automatically when both \f[B]stdin\f[R] @@ -1671,7 +1623,6 @@ bc(1) may also reset on \f[B]SIGINT\f[R] instead of exit, depending on the contents of, or default for, the \f[B]BC_SIGINT_RESET\f[R] environment variable (see the \f[B]ENVIRONMENT VARIABLES\f[R] section). .SH TTY MODE -.PP If \f[B]stdin\f[R], \f[B]stdout\f[R], and \f[B]stderr\f[R] are all connected to a TTY, then \[lq]TTY mode\[rq] is considered to be available, and thus, bc(1) can turn on TTY mode, subject to some @@ -1695,7 +1646,6 @@ required in the bc(1) standard (see the \f[B]STANDARDS\f[R] section), and interactive mode requires only \f[B]stdin\f[R] and \f[B]stdout\f[R] to be connected to a terminal. .SS Command-Line History -.PP Command-line history is only enabled if TTY mode is, i.e., that \f[B]stdin\f[R], \f[B]stdout\f[R], and \f[B]stderr\f[R] are connected to a TTY and the \f[B]BC_TTY_MODE\f[R] environment variable (see the @@ -1703,7 +1653,6 @@ a TTY and the \f[B]BC_TTY_MODE\f[R] environment variable (see the TTY mode. See the \f[B]COMMAND LINE HISTORY\f[R] section for more information. .SS Prompt -.PP If TTY mode is available, then a prompt can be enabled. Like TTY mode itself, it can be turned on or off with an environment variable: \f[B]BC_PROMPT\f[R] (see the \f[B]ENVIRONMENT VARIABLES\f[R] @@ -1724,7 +1673,6 @@ and \f[B]--no-read-prompt\f[R] options. See the \f[B]ENVIRONMENT VARIABLES\f[R] and \f[B]OPTIONS\f[R] sections for more details. .SH SIGNAL HANDLING -.PP Sending a \f[B]SIGINT\f[R] will cause bc(1) to do one of two things. .PP If bc(1) is not in interactive mode (see the \f[B]INTERACTIVE MODE\f[R] @@ -1759,7 +1707,6 @@ The one exception is \f[B]SIGHUP\f[R]; in that case, and only when bc(1) is in TTY mode (see the \f[B]TTY MODE\f[R] section), a \f[B]SIGHUP\f[R] will cause bc(1) to clean up and exit. .SH COMMAND LINE HISTORY -.PP bc(1) supports interactive command-line editing. .PP If bc(1) can be in TTY mode (see the \f[B]TTY MODE\f[R] section), @@ -1777,10 +1724,8 @@ the arrow keys. .PP \f[B]Note\f[R]: tabs are converted to 8 spaces. .SH SEE ALSO -.PP dc(1) .SH STANDARDS -.PP bc(1) is compliant with the IEEE Std 1003.1-2017 (\[lq]POSIX.1-2017\[rq]) specification at https://pubs.opengroup.org/onlinepubs/9699919799/utilities/bc.html . @@ -1797,13 +1742,13 @@ Note that the specification explicitly says that bc(1) only accepts numbers that use a period (\f[B].\f[R]) as a radix point, regardless of the value of \f[B]LC_NUMERIC\f[R]. .SH BUGS -.PP Before version \f[B]6.1.0\f[R], this bc(1) had incorrect behavior for the \f[B]quit\f[R] statement. .PP No other bugs are known. Report bugs at https://git.gavinhoward.com/gavin/bc . .SH AUTHORS -.PP -Gavin D. -Howard <gavin@gavinhoward.com> and contributors. +Gavin D. Howard \c +.MT gavin@gavinhoward.com +.ME \c +\ and contributors. |