---
name: "bison-1.35"
section: "1"
platform: "linux"
package: "bison-1.35"
version: "1.35-4.1"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/bison-1.35"
---

# bison-1.35(1)

GNU Project parser generator (yacc replacement)

## NAME

bison - GNU Project parser generator (yacc replacement)

## SYNOPSIS

**bison** \[ **-b** *file-prefix* \] \[ **--file-prefix=***file-prefix* \] \[ **-d** \] \[ **--defines=***defines-file* \] \[ **-g** \] \[ **--graph=***graph-file* \] \[ **-k** \] \[ **--token-table** \] \[ **-l** \] \[ **--no-lines** \] \[ **-n** \] \[ **--no-parser** \] \[ **-o** *outfile* \] \[ **--output-file=***outfile* \] \[ **-p** *prefix* \] \[ **--name-prefix=***prefix* \] \[ **-t** \] \[ **--debug** \] \[ **-v** \] \[ **--verbose** \] \[ **-V** \] \[ **--version** \] \[ **-y** \] \[ **--yacc** \] \[ **-h** \] \[ **--help** \] \[ **--fixed-output-files** \] file

## DESCRIPTION

*Bison* is a parser generator in the style of [*yacc*(1)](/yacc/1.md). It should be upwardly compatible with input files designed for *yacc*.

Input files should follow the *yacc* convention of ending in **.y**. Unlike *yacc*, the generated files do not have fixed names, but instead use the prefix of the input file. Moreover, if you need to put  *C++* code in the input file, you can end his name by a C++-like extension (.ypp or .y++), then bison will follow your extension to name the  output file (.cpp or .c++). For instance, a grammar description file named **parse.yxx** would produce the generated parser in a file named **parse.tab.cxx**, instead of *yacc*'s **y.tab.c** or old  *Bison* versions **parse.tab.c**.

This description of the options that can be given to *bison* is adapted from the node **Invocation** in the **bison.texinfo** manual, which should be taken as authoritative.

*Bison* supports both traditional single-letter options and mnemonic long option names.  Long option names are indicated with **--** instead of **-**. Abbreviations for option names are allowed as long as they are unique.  When a long option takes an argument, like **--file-prefix**, connect the option name and the argument with **=**.

### OPTIONS

- **-b** *file-prefix*

  - **--file-prefix=***file-prefix*

  Specify a prefix to use for all *bison* output file names.  The names are chosen as if the input file were named *file-prefix***.c**.

- **-d**

  Write an extra output file containing macro definitions for the token type names defined in the grammar and the semantic value type **YYSTYPE**, as well as a few **extern** variable declarations.

  If the parser output file is named *name***.c** then this file is named *name***.h**.

  This output file is essential if you wish to put the definition of **yylex** in a separate source file, because **yylex** needs to be able to refer to token type codes and the variable **yylval**.

- **--defines=***defines-file*

  The behaviour of **--defines** is the same than  **-d** option.  The only difference is that it has an optionnal argument which is  the name of the output filename.

- **-g**

  Output a VCG definition of the LALR(1) grammar automaton computed by Bison. If the grammar file is  **foo.y** , the VCG output file will be **foo.vcg**.

- **--graph=***graph-file*

  The behaviour of  **--graph** is the same than **-g** option. The only difference is that it has an optionnal argument which  is the name of the output graph filename.

- **-k**

  - **--token-table**

  This switch causes the *name***.tab.c** output to include a list of token names in order by their token numbers;  this is defined in the array *yytname*. Also generated are #defines for *YYNTOKENS*, *YYNNTS*, *YYNRULES*, and *YYNSTATES*.

- **-l**

  - **--no-lines**

  Don't put any **#line** preprocessor commands in the parser file. Ordinarily *bison* puts them in the parser file so that the C compiler and debuggers will associate errors with your source file, the grammar file.  This option causes them to associate errors with the parser file, treating it an independent source file in its own right.

- **-n**

  - **--no-parser**

  Do not generate the parser code into the output;  generate only declarations.  The generated *name***.tab.c** file will have only constant declarations.  In addition, a *name***.act** file is generated containing a switch statement body containing all the translated actions.

- **-o** *outfile*

  - **--output-file=***outfile*

  Specify the name *outfile* for the parser file.

  The other output files' names are constructed from *outfile* as described under the **-v** and **-d** switches.

- **-p** *prefix*

  - **--name-prefix=***prefix*

  Rename the external symbols used in the parser so that they start with *prefix* instead of **yy**. The precise list of symbols renamed is **yyparse**, **yylex**, **yyerror**, **yylval**, **yychar**, and **yydebug**.

  For example, if you use **-p c**, the names become **cparse**, **clex**, and so on.

- **-t**

  - **--debug**

  In the parser file, define the macro **YYDEBUG** to 1 if it is not already defined, so that the debugging facilities are compiled.

- **-v**

  - **--verbose**

  Write an extra output file containing verbose descriptions of the parser states and what is done for each type of look-ahead token in that state.

  This file also describes all the conflicts, both those resolved by operator precedence and the unresolved ones.

  The file's name is made by removing **.tab.c** or **.c** from the parser output file name, and adding **.output** instead.

  Therefore, if the input file is **foo.y**, then the parser file is called **foo.tab.c** by default.  As a consequence, the verbose output file is called **foo.output**.

- **-V**

  - **--version**

  Print the version number of *bison* and exit.

- **-h**

  - **--help**

  Print a summary of the options to *bison* and exit.

- **-y**

  - **--yacc**

  - **--fixed-output-files**

  Equivalent to **-o y.tab.c**; the parser output file is called **y.tab.c**, and the other outputs are called **y.output** and **y.tab.h**. The purpose of this switch is to imitate *yacc*'s output file name conventions. Thus, the following shell script can substitute for *yacc*:

  **bison -y $\***

## FILES

/usr/local/share/bison/bison.simple	simple parser\
 /usr/local/share/bison/bison.hairy	complicated parser

## ENVIRONMENT VARIABLES

- BISON\_SIMPLE

  If this is set, it specifies the location in which the **bison.simple** parser can be found.

- BISON\_HAIRY

  If this is set, it specifies the location in which the **bison.hairy** parser can be found.

## SEE ALSO

[*yacc*(1)](/yacc/1.md)\
 The *Bison Reference Manual*, included as the file **bison.texinfo** in the *bison* source distribution.

## DIAGNOSTICS

Self explanatory.