ARGTABLE2(3) Argtable programmer's manual ARGTABLE2(3)NAMEargtable2 - an ANSI C library for parsing GNU style command line
options
SYNOPSIS
#include <argtable2.h>
struct arg_lit
struct arg_int
struct arg_dbl
struct arg_str
struct arg_rex
struct arg_file
struct arg_date
struct arg_rem
struct arg_end
struct arg_lit* arg_lit0(const char *shortopts, const char *longopts, const char *glossary)
struct arg_lit* arg_lit1(const char *shortopts, const char *longopts, const char *glossary)
struct arg_lit* arg_litn(const char *shortopts, const char *longopts, int mincount, int maxcount, const char *glossary)
struct arg_int* arg_int0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary)
struct arg_int* arg_int1(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_int* arg_intn(const char *shortopts, const char *longopts, const char* datatype, int mincount, int maxcount, const char *glossary)
struct arg_dbl* arg_dbl0(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_dbl* arg_dbl1(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_dbl* arg_dbln(const char *shortopts, const char *longopts, const char* datatype, int mincount, int maxcount, const char *glossary)
struct arg_str* arg_str0(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_str* arg_str1(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_str* arg_strn(const char *shortopts, const char *longopts, const char* datatype, int mincount, int maxcount, const char *glossary)
struct arg_rex* arg_rex0(const char* shortopts, const char* longopts, const char* pattern, const char* datatype, int flags, const char* glossary)
struct arg_rex* arg_rex1(const char* shortopts, const char* longopts, const char* pattern, const char* datatype, int flags, const char* glossary)
struct arg_rex* arg_rexn(const char* shortopts, const char* longopts, const char* pattern, const char* datatype, int mincount, int maxcount, int flags, const char* glossary)
struct arg_file* arg_file0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary)
struct arg_file* arg_file1(const char *shortopts, const char *longopts, const char* datatype, const char *glossary)
struct arg_file* arg_filen(const char *shortopts, const char *longopts, const char* datatype, int mincount, int maxcount, const char *glossary)
struct arg_date* arg_date0const char* shortopts, const char* longopts, const char* format, const char* datatype, const char *glossary)
struct arg_date* arg_date1const char* shortopts, const char* longopts, const char* format, const char* datatype, const char *glossary)
struct arg_date* arg_datenconst char* shortopts, const char* longopts, const char* format, const char* datatype, int mincount, int maxcount, const char *glossary)
struct arg_rem* arg_rem(const char *datatype, const char *glossary)
struct arg_end* arg_end(int maxerrors)
int arg_nullcheck(void **argtable)
int arg_parse(int argc, char **argv, void **argtable)
void arg_print_option(FILE *fp, const char *shortopts, const char *longopts, const char *datatype, const char *suffix)
void arg_print_syntax(FILE *fp, void **argtable, const char *suffix)
void arg_print_syntaxv(FILE *fp, void **argtable, const char *suffix)
void arg_print_glossary(FILE *fp, void **argtable, const char *format)
void arg_print_glossary_gnu(FILE *fp, void **argtable)
void arg_print_errors(FILE *fp, struct arg_end *end, const char *progname)
void arg_freetable(void **argtable, size_t n)
DESCRIPTION
Argtable is an ANSI C library for parsing GNU style command line argu‐
ments with a minimum of fuss. It enables the programmer to define their
program's argument syntax directly in the source code as an array of
structs. The command line is then parsed according to that specifica‐
tion and the resulting values stored directly into user-defined program
variables where they are accessible to the main program.
This man page is only for reference. Introductory documentation and
example source code is typically installed under
/usr/local/share/doc/argtable2/ and is also available from the argtable
homepage at http://argtable.sourceforge.net.
Constructing an arg_<xxx> data structure
Each arg_<xxx> struct has it own unique set of constructor functions
(defined above) which are typically of the form:
struct arg_int* arg_int0("f", "foo", "<int>", "the foo factor")
struct arg_int* arg_int1("f", "foo", "<int>", "the foo factor")
struct arg_int* arg_intn("f", "foo", "<int>", 2, 4, "the foo factor")
where arg_int0() and arg_int1() are merely abbreviated forms of
arg_intn(). They are provided for convenience when defining command
line options that have either zero-or-one occurrences (mincount=0,max‐
count=1) or exactly one occurrence (mincount=1,maxcount=1) respec‐
tively.
The shortopts="f" parameter defines the option's short form tag (eg
-f). Multiple alternative tags may be defined by concatenating them
(eg shortopts="abc" defines options -a, -b and -c as equivalent).
Specify shortopts=NULL when no short option is required.
The longopts="foo" parameter defines the option's long form tag (eg
--foo). Multiple alternative long form tags may be separated by commas
(eg longopts="size,limit" defines --size and --limit). Do not include
any whitespace in the longopts string. Specify longopts=NULL when no
long option is required.
If both shortopts and longopts are NULL then the option is an untagged
argument.
The datatype="<int>" parameter is a descriptive string that denotes the
argument data type in error messages, as in --foo=<int>. Specifying
datatype=NULL indicates the default datatype should be used. Specify‐
ing datatype="" effectively disables the datatype display.
The mincount=2 and maxcount=3 parameters specify the minimum and maxi‐
mum number of occurrences of the option on the command line. If the
command line option does not appear the required number of times then
the parser reports a syntax error.
The glossary="the foo factor" parameter is another descriptive string.
It appears only in the glossary table that is generated automatically
by the arg_print_glossary function (described later).
-f, --foo=<int> the foo factor
Specifying a NULL glossary string causes that option to be omitted from
the glossary table.
LITERAL COMMAND LINE OPTIONS
-x, -y, -z, --help, --verbose
struct arg_lit
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of matching command line options */
};
Literal options take no argument values. Upon a successful parse, count
is guaranteed to be within the mincount and maxcount limits specified
at construction.
INTEGER COMMAND LINE OPTIONS
-x2, -z 32MB, --size=734kb, --hex 0x7, --binary 0b10011010, --octal
0o123
Argtable accepts command line integers in decimal (eg 123), hexadecimal
(eg 0xFF12), octal (eg 0o123) and binary (eg 0b0101110) formats. It
also accepts integers that are suffixed by "KB" (x1024), "MB"
(x1048576) or "GB" (x1073741824). All characters are case insensitive
struct arg_int
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of values returned in ival[] */
int *ival; /* array of parsed integer values */
};
Upon a successful parse, count is guaranteed to be within the mincount
and maxcount limits set for the option at construction with the appro‐
priate values store in the ival array. The parser will not accept any
values beyond that limit.
Hint: It is legal to set default values in the ival array prior to
calling the arg_parse function. Argtable will not alter ival entries
for which no command line argument is received.
Hint: Untagged numeric arguments are not recommended because GNU getopt
mistakes negative values (eg -123) for tagged options (eg -1-2 -3).
Tagged arguments (eg -x -123, --tag=-123) do not suffer this problem.
REAL/DOUBLE COMMAND LINE OPTIONS
-x2.234, -y 7e-03, -z-3.3E+6, --pi=3.1415, --tolerance 1.0E-6
struct arg_dbl
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of values returned in dval[] */
double *dval; /* array of parsed double values */
};
Same as arg_int except the parsed values are stored in dval as doubles.
STRING COMMAND LINE OPTIONS
-Dmacro, -t mytitle, -m "my message string", --title="hello world"
struct arg_str
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of strings returned in sval[] */
const char **sval; /* array of pointers to parsed argument strings */
};
Same as arg_int except pointers to the parsed strings are returned in
sval rather than a separate copy of the string. Indeed, these pointers
actually reference the original string buffers stored in argv[], so
their contents should not be altered. However, it is legal to ini‐
tialise the string pointers in the sval array to reference user-sup‐
plied default strings prior to calling arg_parse. Argtable will only
alter the contents of sval when matching command line arguments are
detected.
REGULAR EXPRESSION COMMAND LINE OPTIONS
commit, update, --command=commit, --command=update
struct arg_rex
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of strings returned in sval[] */
const char **sval; /* array of pointers to parsed argument strings */
};
Similar to arg_str except the string argument values are only accepted
if they match a predefined regular expression. Regular expressions are
useful for matching command line keywords, particularly if case insen‐
sitive strings or pattern matching is required. The regular expression
is defined by the pattern parameter passed to the arg_rex constructor
and evaluated using regex. Its behaviour can be controlled via stan‐
dard regex bit flags. These are passed to argtable via the flags param‐
eter in the arg_rex constructor. However the only two of the standard
regex flags are relevant to argtable, namely REG_EXTENDED (use extended
regular expressions rather than basic ones) and REG_ICASE (ignore
case). These flags may be logically ORed if desired. See regex(3) for
more details of regular expression matching.
Restrictions: Argtable does not support arg_rex functionality under Mi‐
crosoft Windows platforms because the Microsoft compilers do include
the necessary regex support as standard.
FILENAME COMMAND LINE OPTIONS
-o myfile, -Ihome/foo/bar, --input=~/doc/letter.txt, --name a.out
struct arg_file
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of filename strings returned */
const char **filename; /* pointer to full filename string */
const char **basename; /* pointer to filename excluding leading path */
const char **extension; /* pointer to the filename extension */
};
Similar to arg_str but the argument strings are presumed to refer to
filenames hence some additional parsing is done to separate out the
filename's basename and extension (if they exist). The three arrays
filename[], basename[], extension[] each store up to maxcount entries,
and the i'th entry of each of these arrays refer to different compo‐
nents of the same string buffer.
For example, -o /home/heitmann/mydir/foo.txt would be parsed as:
filename[i] = "/home/heitmann/mydir/foo.txt"
basename[i] = "foo.txt"
extension[i] = ".txt"
If the filename has no leading path then the basename is the same as
the filename. If no extension could be identified then it is given as
NULL. Extensions are considered as all text from the last dot in the
filename.
Hint: Argtable only ever treats the filenames as strings and never
attempts to open them as files or perform any directory lookups on
them.
DATE/TIME COMMAND LINE OPTIONS
12/31/04, -d 1982-11-28, --time 23:59
struct arg_date
{
struct arg_hdr hdr; /* internal argtable header */
const char *format; /* user-supplied date format string that was passed to constructor */
int count; /* number of datestamps returned in tmval[] */
struct tm *tmval; /* array of datestamps */
};
Accepts a timestamp string from the command line and converts it to
struct tm format using the system strptime function. The time format is
defined by the format string passed to the arg_date constructor, and is
passed directly to strptime. See strptime(3) for more details on the
format string.
Restrictions: Argtable does not support arg_date functionality under
Microsoft Windows because the Microsoft compilers do include the neces‐
sary strptime support as standard.
REMARK OPTIONS
struct arg_rem
{
struct arg_hdr hdr; /* internal argtable header */
};
The arg_rem struct is a dummy struct in the sense it does not represent
a command line option to be parsed. Instead it provides a means to
include additional datatype and glossary strings in the output of the
arg_print_syntax, arg_print_syntaxv, and arg_print_glossary functions.
As such, arg_rem structs may be used in the argument table to insert
additional lines of text into the glossary descriptions or to insert
additional text fields into the syntax description.
END-OF-TABLE OPTION
struct arg_end
{
struct arg_hdr hdr; /* internal argtable header */
int count; /* number of errors returned */
int *error; /* array of error codes */
void **parent; /* pointers to the erroneous command line options */
const char **argval; /* pointers to the erroneous command line argument values */
};
Every argument table must have an arg_end structure as its last entry.
It marks the end of an argument table and stores the error codes generated
by the parser as it processed the argument table.
The maxerrors parameter passed to the arg_end constructor
specifies the maximum number of errors that the structure can store.
Any further errors are discarded and replaced with the single error code
ARG_ELIMIT which is later reported to the user by the message "too many errors".
A maxerrors limit of 20 is quite reasonable.
The arg_print_errors function will print the errors stored
in the arg_end struct in the same order as they occurred,
so there is no need to understand the internals of the arg_end struct.
FUNCTION REFERENCE
int arg_nullcheck (void **argtable)
Returns non-zero if the argtable[] array contains any NULL entries up
until the terminating arg_end* entry. Returns zero otherwise.
int arg_parse (int argc, char **argv, void **argtable)
Parse the command line arguments in argv[] using the command line syn‐
tax specified in argtable[], returning the number of errors encoun‐
tered. Error details are recorded in the argument table's arg_end
structure from where they can be displayed later with the
arg_print_errors function. Upon a successful parse, the arg_xxx struc‐
tures referenced in argtable[] will contain the argument values
extracted from the command line.
void arg_print_option (FILE *fp, const char *shortopts, const char *lon‐
gopts, const char *datatype, const char *suffix)
This function prints an option's syntax, as in -K|--scalar=<int>, where
the short options, long options, and datatype are all given as parame‐
ters of this function. It is primarily used within the arg_xxx struc‐
tures' errorfn functions as a way of displaying an option's syntax
inside of error messages. However, it can also be used in user code if
desired. The suffix string is provided as a convenience for appending
newlines and so forth to the end of the display and can be given as
NULL if not required.
void arg_print_syntax (FILE *fp, void **argtable, const char *suffix)
Prints the GNU style command line syntax for the given argument table,
as in: [-abcv] [--scalar=<n>] [-o myfile] <file> [<file>]
The suffix string is provided as a convenience for appending newlines
and so forth to the end of the display and can be given as NULL if not
required.
void arg_print_syntaxv (FILE *fp, void **argtable, const char *suffix)
Prints the verbose form of the command line syntax for the given argu‐
ment table, as in: [-a] [-b] [-c] [--scalar=<n>] [-o myfile] [-v|--ver‐
bose] <file> [<file>]
The suffix string is provided as a convenience for appending newlines
and so forth to the end of the display and can be given as NULL if not
required.
void arg_print_glossary (FILE *fp, void **argtable, const char *format)
Prints a glossary table describing each option in the given argument
table. The format string is passed to printf to control the formatting
of each entry in the the glossary. It must have exactly two "%s" for‐
mat parameters as in "%-25s %s\n", the first is for the option's syntax
and the second for its glossary string. If an option's glossary string
is NULL then that option in omitted from the glossary display.
void arg_print_glossary_gnu (FILE *fp, void **argtable)
An alternate form of arg_print_glossary() that prints the glossary
using strict GNU formatting conventions wherein long options are verti‐
cally aligned in a second column, and lines are wrapped at 80 charac‐
ters.
void arg_print_errors (FILE *fp, struct arg_end *end, const char *progname)
Prints the details of all errors stored in the end data structure. The
progname string is prepended to each error message.
void arg_freetable (void ** argtable, size_t n)
Deallocates the memory used by each arg_xxx struct referenced by
argtable[]. It does this by calling free for each of the n pointers in
the argtable array and then nulling them for safety.
FILES
/usr/local/include/argtable2.h
/usr/local/lib/libargtable2.a
/usr/local/lib/libargtable2.so
/usr/local/man3/argtable2.3
/usr/local/share/doc/argtable2/
/usr/local/share/doc/argtable2/example/
AUTHOR
Stewart Heitmann <sheitmann@users.sourceforge.net>
Argtable2-13 Jan 2008 ARGTABLE2(3)
