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@c Automatically generated from *.c and others (the comments before

@c each entry tell you which file and where in that file).  DO NOT EDIT!

@c Edit the *.c files, configure with --enable-maintainer-mode,

@c and let gather-docs build you a new copy.

@c safe-ctype.c:25

@defvr Extension HOST_CHARSET

This macro indicates the basic character set and encoding used by the

host: more precisely, the encoding used for character constants in

preprocessor @samp{#if} statements (the C "execution character set").

It is defined by @file{safe-ctype.h}, and will be an integer constant

with one of the following values:

@ftable @code

@item HOST_CHARSET_UNKNOWN

The host character set is unknown - that is, not one of the next two

possibilities.

@item HOST_CHARSET_ASCII

The host character set is ASCII.

@item HOST_CHARSET_EBCDIC

The host character set is some variant of EBCDIC.  (Only one of the

nineteen EBCDIC varying characters is tested; exercise caution.)

@end ftable

@end defvr

@c alloca.c:26

@deftypefn Replacement void* alloca (size_t @var{size})

This function allocates memory which will be automatically reclaimed

after the procedure exits.  The @libib{} implementation does not free

the memory immediately but will do so eventually during subsequent

calls to this function.  Memory is allocated using @code{xmalloc} under

normal circumstances.

The header file @file{alloca-conf.h} can be used in conjunction with the

GNU Autoconf test @code{AC_FUNC_ALLOCA} to test for and properly make

available this function.  The @code{AC_FUNC_ALLOCA} test requires that

client code use a block of preprocessor code to be safe (see the Autoconf

manual for more); this header incorporates that logic and more, including

the possibility of a GCC built-in function.

@end deftypefn

@c asprintf.c:32

@deftypefn Extension int asprintf (char **@var{resptr}, const char *@var{format}, ...)

Like @code{sprintf}, but instead of passing a pointer to a buffer, you

pass a pointer to a pointer.  This function will compute the size of

the buffer needed, allocate memory with @code{malloc}, and store a

pointer to the allocated memory in @code{*@var{resptr}}.  The value

returned is the same as @code{sprintf} would return.  If memory could

not be allocated, minus one is returned and @code{NULL} is stored in

@code{*@var{resptr}}.

@end deftypefn

@c atexit.c:6

@deftypefn Supplemental int atexit (void (*@var{f})())

Causes function @var{f} to be called at exit.  Returns 0.

@end deftypefn

@c basename.c:6

@deftypefn Supplemental char* basename (const char *@var{name})

Returns a pointer to the last component of pathname @var{name}.

Behavior is undefined if the pathname ends in a directory separator.

@end deftypefn

@c bcmp.c:6

@deftypefn Supplemental int bcmp (char *@var{x}, char *@var{y}, int @var{count})

Compares the first @var{count} bytes of two areas of memory.  Returns

zero if they are the same, nonzero otherwise.  Returns zero if

@var{count} is zero.  A nonzero result only indicates a difference,

it does not indicate any sorting order (say, by having a positive

result mean @var{x} sorts before @var{y}).

@end deftypefn

@c bcopy.c:3

@deftypefn Supplemental void bcopy (char *@var{in}, char *@var{out}, int @var{length})

Copies @var{length} bytes from memory region @var{in} to region

@var{out}.  The use of @code{bcopy} is deprecated in new programs.

@end deftypefn

@c bsearch.c:33

@deftypefn Supplemental void* bsearch (const void *@var{key}, const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, int (*@var{compar})(const void *, const void *))

Performs a search over an array of @var{nmemb} elements pointed to by

@var{base} for a member that matches the object pointed to by @var{key}.

The size of each member is specified by @var{size}.  The array contents

should be sorted in ascending order according to the @var{compar}

comparison function.  This routine should take two arguments pointing to

the @var{key} and to an array member, in that order, and should return an

integer less than, equal to, or greater than zero if the @var{key} object

is respectively less than, matching, or greater than the array member.

@end deftypefn

@c argv.c:124

@deftypefn Extension char** buildargv (char *@var{sp})

Given a pointer to a string, parse the string extracting fields

separated by whitespace and optionally enclosed within either single

or double quotes (which are stripped off), and build a vector of

pointers to copies of the string for each field.  The input string

remains unchanged.  The last element of the vector is followed by a

@code{NULL} element.

All of the memory for the pointer array and copies of the string

is obtained from @code{malloc}.  All of the memory can be returned to the

system with the single function call @code{freeargv}, which takes the

returned result of @code{buildargv}, as it's argument.

Returns a pointer to the argument vector if successful.  Returns

@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient

memory to complete building the argument vector.

If the input is a null string (as opposed to a @code{NULL} pointer),

then buildarg returns an argument vector that has one arg, a null

string.

@end deftypefn

@c bzero.c:6

@deftypefn Supplemental void bzero (char *@var{mem}, int @var{count})

Zeros @var{count} bytes starting at @var{mem}.  Use of this function

is deprecated in favor of @code{memset}.

@end deftypefn

@c calloc.c:6

@deftypefn Supplemental void* calloc (size_t @var{nelem}, size_t @var{elsize})

Uses @code{malloc} to allocate storage for @var{nelem} objects of

@var{elsize} bytes each, then zeros the memory.

@end deftypefn

@c choose-temp.c:42

@deftypefn Extension char* choose_temp_base (void)

Return a prefix for temporary file names or @code{NULL} if unable to

find one.  The current directory is chosen if all else fails so the

program is exited if a temporary directory can't be found (@code{mktemp}

fails).  The buffer for the result is obtained with @code{xmalloc}.

This function is provided for backwards compatibility only.  Its use is

not recommended.

@end deftypefn

@c make-temp-file.c:87

@deftypefn Replacement char* choose_tmpdir ()

Returns a pointer to a directory path suitable for creating temporary

files in.

@end deftypefn

@c clock.c:27

@deftypefn Supplemental long clock (void)

Returns an approximation of the CPU time used by the process as a

@code{clock_t}; divide this number by @samp{CLOCKS_PER_SEC} to get the

number of seconds used.

@end deftypefn

@c concat.c:24

@deftypefn Extension char* concat (const char *@var{s1}, const char *@var{s2}, @dots{}, @code{NULL})

Concatenate zero or more of strings and return the result in freshly

@code{xmalloc}ed memory.  Returns @code{NULL} if insufficient memory is

available.  The argument list is terminated by the first @code{NULL}

pointer encountered.  Pointers to empty strings are ignored.

@end deftypefn

@c argv.c:52

@deftypefn Extension char** dupargv (char **@var{vector})

Duplicate an argument vector.  Simply scans through @var{vector},

duplicating each argument until the terminating @code{NULL} is found.

Returns a pointer to the argument vector if successful.  Returns

@code{NULL} if there is insufficient memory to complete building the

argument vector.

@end deftypefn

@c strerror.c:567

@deftypefn Extension int errno_max (void)

Returns the maximum @code{errno} value for which a corresponding

symbolic name or message is available.  Note that in the case where we

use the @code{sys_errlist} supplied by the system, it is possible for

there to be more symbolic names than messages, or vice versa.  In

fact, the manual page for @code{perror(3C)} explicitly warns that one

should check the size of the table (@code{sys_nerr}) before indexing

it, since new error codes may be added to the system before they are

added to the table.  Thus @code{sys_nerr} might be smaller than value

implied by the largest @code{errno} value defined in @code{<errno.h>}.

We return the maximum value that can be used to obtain a meaningful

symbolic name or message.

@end deftypefn

@c argv.c:348

@deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})

The @var{argcp} and @code{argvp} arguments are pointers to the usual

@code{argc} and @code{argv} arguments to @code{main}.  This function

looks for arguments that begin with the character @samp{@@}.  Any such

arguments are interpreted as ``response files''.  The contents of the

response file are interpreted as additional command line options.  In

particular, the file is separated into whitespace-separated strings;

each such string is taken as a command-line option.  The new options

are inserted in place of the option naming the response file, and

@code{*argcp} and @code{*argvp} will be updated.  If the value of

@code{*argvp} is modified by this function, then the new value has

been dynamically allocated and can be deallocated by the caller with

@code{freeargv}.  However, most callers will simply call

@code{expandargv} near the beginning of @code{main} and allow the

operating system to free the memory when the program exits.

@end deftypefn

@c fdmatch.c:23

@deftypefn Extension int fdmatch (int @var{fd1}, int @var{fd2})

Check to see if two open file descriptors refer to the same file.

This is useful, for example, when we have an open file descriptor for

an unnamed file, and the name of a file that we believe to correspond

to that fd.  This can happen when we are exec'd with an already open

file (@code{stdout} for example) or from the SVR4 @file{/proc} calls

that return open file descriptors for mapped address spaces.  All we

have to do is open the file by name and check the two file descriptors

for a match, which is done by comparing major and minor device numbers

and inode numbers.

@end deftypefn

@c fopen_unlocked.c:48

@deftypefn Extension {FILE *} fdopen_unlocked (int @var{fildes}, const char * @var{mode})

Opens and returns a @code{FILE} pointer via @code{fdopen}.  If the

operating system supports it, ensure that the stream is setup to avoid

any multi-threaded locking.  Otherwise return the @code{FILE} pointer

unchanged.

@end deftypefn

@c ffs.c:3

@deftypefn Supplemental int ffs (int @var{valu})

Find the first (least significant) bit set in @var{valu}.  Bits are

numbered from right to left, starting with bit 1 (corresponding to the

value 1).  If @var{valu} is zero, zero is returned.

@end deftypefn

@c filename_cmp.c:32

@deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})

Return zero if the two file names @var{s1} and @var{s2} are equivalent.

If not equivalent, the returned value is similar to what @code{strcmp}

would return.  In other words, it returns a negative value if @var{s1}

is less than @var{s2}, or a positive value if @var{s2} is greater than

@var{s2}.

This function does not normalize file names.  As a result, this function

will treat filenames that are spelled differently as different even in

the case when the two filenames point to the same underlying file.

However, it does handle the fact that on DOS-like file systems, forward

and backward slashes are equal.

@end deftypefn

@c fnmatch.txh:1

@deftypefn Replacement int fnmatch (const char *@var{pattern}, const char *@var{string}, int @var{flags})

Matches @var{string} against @var{pattern}, returning zero if it

matches, @code{FNM_NOMATCH} if not.  @var{pattern} may contain the

wildcards @code{?} to match any one character, @code{*} to match any

zero or more characters, or a set of alternate characters in square

brackets, like @samp{[a-gt8]}, which match one character (@code{a}

through @code{g}, or @code{t}, or @code{8}, in this example) if that one

character is in the set.  A set may be inverted (i.e., match anything

except what's in the set) by giving @code{^} or @code{!} as the first

character in the set.  To include those characters in the set, list them

as anything other than the first character of the set.  To include a

dash in the set, list it last in the set.  A backslash character makes

the following character not special, so for example you could match

against a literal asterisk with @samp{\*}.  To match a literal

backslash, use @samp{\\}.

@code{flags} controls various aspects of the matching process, and is a

boolean OR of zero or more of the following values (defined in

@code{<fnmatch.h>}):

@table @code

@item FNM_PATHNAME

@itemx FNM_FILE_NAME

@var{string} is assumed to be a path name.  No wildcard will ever match

@code{/}.

@item FNM_NOESCAPE

Do not interpret backslashes as quoting the following special character.

@item FNM_PERIOD

A leading period (at the beginning of @var{string}, or if

@code{FNM_PATHNAME} after a slash) is not matched by @code{*} or

@code{?} but must be matched explicitly.

@item FNM_LEADING_DIR

Means that @var{string} also matches @var{pattern} if some initial part

of @var{string} matches, and is followed by @code{/} and zero or more

characters.  For example, @samp{foo*} would match either @samp{foobar}

or @samp{foobar/grill}.

@item FNM_CASEFOLD

Ignores case when performing the comparison.

@end table

@end deftypefn

@c fopen_unlocked.c:39

@deftypefn Extension {FILE *} fopen_unlocked (const char *@var{path}, const char * @var{mode})

Opens and returns a @code{FILE} pointer via @code{fopen}.  If the

operating system supports it, ensure that the stream is setup to avoid

any multi-threaded locking.  Otherwise return the @code{FILE} pointer

unchanged.

@end deftypefn

@c argv.c:97

@deftypefn Extension void freeargv (char **@var{vector})

Free an argument vector that was built using @code{buildargv}.  Simply

scans through @var{vector}, freeing the memory for each argument until

the terminating @code{NULL} is found, and then frees @var{vector}

itself.

@end deftypefn

@c fopen_unlocked.c:57

@deftypefn Extension {FILE *} freopen_unlocked (const char * @var{path}, const char * @var{mode}, FILE * @var{stream})

Opens and returns a @code{FILE} pointer via @code{freopen}.  If the

operating system supports it, ensure that the stream is setup to avoid

any multi-threaded locking.  Otherwise return the @code{FILE} pointer

unchanged.

@end deftypefn

@c getruntime.c:82

@deftypefn Replacement long get_run_time (void)

Returns the time used so far, in microseconds.  If possible, this is

the time used by this process, else it is the elapsed time since the

process started.

@end deftypefn

@c getcwd.c:6

@deftypefn Supplemental char* getcwd (char *@var{pathname}, int @var{len})

Copy the absolute pathname for the current working directory into

@var{pathname}, which is assumed to point to a buffer of at least

@var{len} bytes, and return a pointer to the buffer.  If the current

directory's path doesn't fit in @var{len} characters, the result is

@code{NULL} and @code{errno} is set.  If @var{pathname} is a null pointer,

@code{getcwd} will obtain @var{len} bytes of space using

@code{malloc}.

@end deftypefn

@c getpagesize.c:5

@deftypefn Supplemental int getpagesize (void)

Returns the number of bytes in a page of memory.  This is the

granularity of many of the system memory management routines.  No

guarantee is made as to whether or not it is the same as the basic

memory management hardware page size.

@end deftypefn

@c getpwd.c:5

@deftypefn Supplemental char* getpwd (void)

Returns the current working directory.  This implementation caches the

result on the assumption that the process will not call @code{chdir}

between calls to @code{getpwd}.

@end deftypefn

@c gettimeofday.c:12

@deftypefn Supplemental int gettimeofday (struct timeval *@var{tp}, void *@var{tz})

Writes the current time to @var{tp}.  This implementation requires

that @var{tz} be NULL.  Returns 0 on success, -1 on failure.

@end deftypefn

@c hex.c:33

@deftypefn Extension void hex_init (void)

Initializes the array mapping the current character set to

corresponding hex values.  This function must be called before any

call to @code{hex_p} or @code{hex_value}.  If you fail to call it, a

default ASCII-based table will normally be used on ASCII systems.

@end deftypefn

@c hex.c:42

@deftypefn Extension int hex_p (int @var{c})

Evaluates to non-zero if the given character is a valid hex character,

or zero if it is not.  Note that the value you pass will be cast to

@code{unsigned char} within the macro.

@end deftypefn

@c hex.c:50

@deftypefn Extension {unsigned int} hex_value (int @var{c})

Returns the numeric equivalent of the given character when interpreted

as a hexadecimal digit.  The result is undefined if you pass an

invalid hex digit.  Note that the value you pass will be cast to

@code{unsigned char} within the macro.

The @code{hex_value} macro returns @code{unsigned int}, rather than

signed @code{int}, to make it easier to use in parsing addresses from

hex dump files: a signed @code{int} would be sign-extended when

converted to a wider unsigned type --- like @code{bfd_vma}, on some

systems.

@end deftypefn

@c index.c:5

@deftypefn Supplemental char* index (char *@var{s}, int @var{c})

Returns a pointer to the first occurrence of the character @var{c} in

the string @var{s}, or @code{NULL} if not found.  The use of @code{index} is

deprecated in new programs in favor of @code{strchr}.

@end deftypefn

@c insque.c:6

@deftypefn Supplemental void insque (struct qelem *@var{elem}, struct qelem *@var{pred})

@deftypefnx Supplemental void remque (struct qelem *@var{elem})

Routines to manipulate queues built from doubly linked lists.  The

@code{insque} routine inserts @var{elem} in the queue immediately

after @var{pred}.  The @code{remque} routine removes @var{elem} from

its containing queue.  These routines expect to be passed pointers to

structures which have as their first members a forward pointer and a

back pointer, like this prototype (although no prototype is provided):

@example

struct qelem @{

  struct qelem *q_forw;

  struct qelem *q_back;

  char q_data[];

@};

@end example

@end deftypefn

@c safe-ctype.c:46

@deffn  Extension ISALPHA  (@var{c})

@deffnx Extension ISALNUM  (@var{c})

@deffnx Extension ISBLANK  (@var{c})

@deffnx Extension ISCNTRL  (@var{c})

@deffnx Extension ISDIGIT  (@var{c})

@deffnx Extension ISGRAPH  (@var{c})

@deffnx Extension ISLOWER  (@var{c})

@deffnx Extension ISPRINT  (@var{c})

@deffnx Extension ISPUNCT  (@var{c})

@deffnx Extension ISSPACE  (@var{c})

@deffnx Extension ISUPPER  (@var{c})

@deffnx Extension ISXDIGIT (@var{c})

These twelve macros are defined by @file{safe-ctype.h}.  Each has the

same meaning as the corresponding macro (with name in lowercase)

defined by the standard header @file{ctype.h}.  For example,

@code{ISALPHA} returns true for alphabetic characters and false for

others.  However, there are two differences between these macros and

those provided by @file{ctype.h}:

@itemize @bullet

@item These macros are guaranteed to have well-defined behavior for all

values representable by @code{signed char} and @code{unsigned char}, and

for @code{EOF}.

@item These macros ignore the current locale; they are true for these

fixed sets of characters:

@multitable {@code{XDIGIT}} {yada yada yada yada yada yada yada yada}

@item @code{ALPHA}  @tab @kbd{A-Za-z}

@item @code{ALNUM}  @tab @kbd{A-Za-z0-9}

@item @code{BLANK}  @tab @kbd{space tab}

@item @code{CNTRL}  @tab @code{!PRINT}

@item @code{DIGIT}  @tab @kbd{0-9}

@item @code{GRAPH}  @tab @code{ALNUM || PUNCT}

@item @code{LOWER}  @tab @kbd{a-z}

@item @code{PRINT}  @tab @code{GRAPH ||} @kbd{space}

@item @code{PUNCT}  @tab @kbd{`~!@@#$%^&*()_-=+[@{]@}\|;:'",<.>/?}

@item @code{SPACE}  @tab @kbd{space tab \n \r \f \v}

@item @code{UPPER}  @tab @kbd{A-Z}

@item @code{XDIGIT} @tab @kbd{0-9A-Fa-f}

@end multitable

Note that, if the host character set is ASCII or a superset thereof,

all these macros will return false for all values of @code{char} outside

the range of 7-bit ASCII.  In particular, both ISPRINT and ISCNTRL return

false for characters with numeric values from 128 to 255.

@end itemize

@end deffn

@c safe-ctype.c:95

@deffn  Extension ISIDNUM         (@var{c})

@deffnx Extension ISIDST          (@var{c})

@deffnx Extension IS_VSPACE       (@var{c})

@deffnx Extension IS_NVSPACE      (@var{c})

@deffnx Extension IS_SPACE_OR_NUL (@var{c})

@deffnx Extension IS_ISOBASIC     (@var{c})

These six macros are defined by @file{safe-ctype.h} and provide

additional character classes which are useful when doing lexical

analysis of C or similar languages.  They are true for the following

sets of characters:

@multitable {@code{SPACE_OR_NUL}} {yada yada yada yada yada yada yada yada}

@item @code{IDNUM}        @tab @kbd{A-Za-z0-9_}

@item @code{IDST}         @tab @kbd{A-Za-z_}

@item @code{VSPACE}       @tab @kbd{\r \n}

@item @code{NVSPACE}      @tab @kbd{space tab \f \v \0}

@item @code{SPACE_OR_NUL} @tab @code{VSPACE || NVSPACE}

@item @code{ISOBASIC}     @tab @code{VSPACE || NVSPACE || PRINT}

@end multitable

@end deffn

@c lbasename.c:23

@deftypefn Replacement {const char*} lbasename (const char *@var{name})

Given a pointer to a string containing a typical pathname

(@samp{/usr/src/cmd/ls/ls.c} for example), returns a pointer to the

last component of the pathname (@samp{ls.c} in this case).  The

returned pointer is guaranteed to lie within the original

string.  This latter fact is not true of many vendor C

libraries, which return special strings or modify the passed

strings for particular input.

In particular, the empty string returns the same empty string,

and a path ending in @code{/} returns the empty string after it.

@end deftypefn

@c lrealpath.c:25

@deftypefn Replacement {const char*} lrealpath (const char *@var{name})

Given a pointer to a string containing a pathname, returns a canonical

version of the filename.  Symlinks will be resolved, and ``.'' and ``..''

components will be simplified.  The returned value will be allocated using

@code{malloc}, or @code{NULL} will be returned on a memory allocation error.

@end deftypefn

@c make-relative-prefix.c:24

@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix})

Given three paths @var{progname}, @var{bin_prefix}, @var{prefix},

return the path that is in the same position relative to

@var{progname}'s directory as @var{prefix} is relative to

@var{bin_prefix}.  That is, a string starting with the directory

portion of @var{progname}, followed by a relative pathname of the

difference between @var{bin_prefix} and @var{prefix}.

If @var{progname} does not contain any directory separators,

@code{make_relative_prefix} will search @env{PATH} to find a program

named @var{progname}.  Also, if @var{progname} is a symbolic link,

the symbolic link will be resolved.

For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta},

@var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is

@code{/red/green/blue/gcc}, then this function will return

@code{/red/green/blue/../../omega/}.

The return value is normally allocated via @code{malloc}.  If no

relative prefix can be found, return @code{NULL}.

@end deftypefn

@c make-temp-file.c:137

@deftypefn Replacement char* make_temp_file (const char *@var{suffix})

Return a temporary file name (as a string) or @code{NULL} if unable to

create one.  @var{suffix} is a suffix to append to the file name.  The

string is @code{malloc}ed, and the temporary file has been created.

@end deftypefn

@c memchr.c:3

@deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, size_t @var{n})

This function searches memory starting at @code{*@var{s}} for the

character @var{c}.  The search only ends with the first occurrence of

@var{c}, or after @var{length} characters; in particular, a null

character does not terminate the search.  If the character @var{c} is

found within @var{length} characters of @code{*@var{s}}, a pointer

to the character is returned.  If @var{c} is not found, then @code{NULL} is

returned.

@end deftypefn

@c memcmp.c:6

@deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, size_t @var{count})

Compares the first @var{count} bytes of two areas of memory.  Returns

zero if they are the same, a value less than zero if @var{x} is

lexically less than @var{y}, or a value greater than zero if @var{x}

is lexically greater than @var{y}.  Note that lexical order is determined

as if comparing unsigned char arrays.

@end deftypefn

@c memcpy.c:6

@deftypefn Supplemental void* memcpy (void *@var{out}, const void *@var{in}, size_t @var{length})

Copies @var{length} bytes from memory region @var{in} to region

@var{out}.  Returns a pointer to @var{out}.

@end deftypefn

@c memmove.c:6

@deftypefn Supplemental void* memmove (void *@var{from}, const void *@var{to}, size_t @var{count})

Copies @var{count} bytes from memory area @var{from} to memory area

@var{to}, returning a pointer to @var{to}.

@end deftypefn

@c mempcpy.c:23

@deftypefn Supplemental void* mempcpy (void *@var{out}, const void *@var{in}, size_t @var{length})

Copies @var{length} bytes from memory region @var{in} to region

@var{out}.  Returns a pointer to @var{out} + @var{length}.

@end deftypefn

@c memset.c:6

@deftypefn Supplemental void* memset (void *@var{s}, int @var{c}, size_t @var{count})

Sets the first @var{count} bytes of @var{s} to the constant byte

@var{c}, returning a pointer to @var{s}.

@end deftypefn

@c mkstemps.c:58

@deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len})

Generate a unique temporary file name from @var{pattern}.

@var{pattern} has the form:

@example

   @var{path}/ccXXXXXX@var{suffix}

@end example

@var{suffix_len} tells us how long @var{suffix} is (it can be zero

length).  The last six characters of @var{pattern} before @var{suffix}

must be @samp{XXXXXX}; they are replaced with a string that makes the

filename unique.  Returns a file descriptor open on the file for

reading and writing.

@end deftypefn

@c pexecute.txh:266

@deftypefn Extension void pex_free (struct pex_obj @var{obj})

Clean up and free all data associated with @var{obj}.

@end deftypefn

@c pexecute.txh:241

@deftypefn Extension int pex_get_status (struct pex_obj *@var{obj}, int @var{count}, int *@var{vector})

Returns the exit status of all programs run using @var{obj}.

@var{count} is the number of results expected.  The results will be

placed into @var{vector}.  The results are in the order of the calls

to @code{pex_run}.  Returns 0 on error, 1 on success.

@end deftypefn

@c pexecute.txh:250

@deftypefn Extension int pex_get_times (struct pex_obj *@var{obj}, int @var{count}, struct pex_time *@var{vector})

Returns the process execution times of all programs run using

@var{obj}.  @var{count} is the number of results expected.  The

results will be placed into @var{vector}.  The results are in the

order of the calls to @code{pex_run}.  Returns 0 on error, 1 on

success.

@code{struct pex_time} has the following fields of the type

@code{unsigned long}: @code{user_seconds},

@code{user_microseconds}, @code{system_seconds},

@code{system_microseconds}.  On systems which do not support reporting

process times, all the fields will be set to @code{0}.

@end deftypefn

@c pexecute.txh:2

@deftypefn Extension {struct pex_obj *} pex_init (int @var{flags}, const char *@var{pname}, const char *@var{tempbase})

Prepare to execute one or more programs, with standard output of each

program fed to standard input of the next.  This is a system

independent interface to execute a pipeline.

@var{flags} is a bitwise combination of the following:

@table @code

@vindex PEX_RECORD_TIMES

@item PEX_RECORD_TIMES

Record subprocess times if possible.

@vindex PEX_USE_PIPES

@item PEX_USE_PIPES

Use pipes for communication between processes, if possible.

@vindex PEX_SAVE_TEMPS

@item PEX_SAVE_TEMPS

Don't delete temporary files used for communication between

processes.

@end table

@var{pname} is the name of program to be executed, used in error

messages.  @var{tempbase} is a base name to use for any required

temporary files; it may be @code{NULL} to use a randomly chosen name.

@end deftypefn

@c pexecute.txh:155

@deftypefn Extension {FILE *} pex_input_file (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{in_name})

Return a stream for a temporary file to pass to the first program in

the pipeline as input.

The name of the input file is chosen according to the same rules

@code{pex_run} uses to choose output file names, based on

@var{in_name}, @var{obj} and the @code{PEX_SUFFIX} bit in @var{flags}.

Don't call @code{fclose} on the returned stream; the first call to

@code{pex_run} closes it automatically.

If @var{flags} includes @code{PEX_BINARY_OUTPUT}, open the stream in

binary mode; otherwise, open it in the default mode.  Including

@code{PEX_BINARY_OUTPUT} in @var{flags} has no effect on Unix.

@end deftypefn

@c pexecute.txh:172

@deftypefn Extension {FILE *} pex_input_pipe (struct pex_obj *@var{obj}, int @var{binary})

Return a stream @var{fp} for a pipe connected to the standard input of

the first program in the pipeline; @var{fp} is opened for writing.

You must have passed @code{PEX_USE_PIPES} to the @code{pex_init} call

that returned @var{obj}.

You must close @var{fp} using @code{fclose} yourself when you have

finished writing data to the pipeline.

The file descriptor underlying @var{fp} is marked not to be inherited

by child processes.

On systems that do not support pipes, this function returns

@code{NULL}, and sets @code{errno} to @code{EINVAL}.  If you would

like to write code that is portable to all systems the @code{pex}

functions support, consider using @code{pex_input_file} instead.

There are two opportunities for deadlock using

@code{pex_input_pipe}:

@itemize @bullet

@item

Most systems' pipes can buffer only a fixed amount of data; a process

that writes to a full pipe blocks.  Thus, if you write to @file{fp}

before starting the first process, you run the risk of blocking when

there is no child process yet to read the data and allow you to

continue.  @code{pex_input_pipe} makes no promises about the

size of the pipe's buffer, so if you need to write any data at all

before starting the first process in the pipeline, consider using

@code{pex_input_file} instead.

@item

Using @code{pex_input_pipe} and @code{pex_read_output} together

may also cause deadlock.  If the output pipe fills up, so that each

program in the pipeline is waiting for the next to read more data, and

you fill the input pipe by writing more data to @var{fp}, then there

is no way to make progress: the only process that could read data from

the output pipe is you, but you are blocked on the input pipe.

@end itemize

@end deftypefn

@c pexecute.txh:272

@deftypefn Extension {const char *} pex_one (int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{pname}, const char *@var{outname}, const char *@var{errname}, int *@var{status}, int *@var{err})

An interface to permit the easy execution of a

single program.  The return value and most of the parameters are as

for a call to @code{pex_run}.  @var{flags} is restricted to a

combination of @code{PEX_SEARCH}, @code{PEX_STDERR_TO_STDOUT}, and

@code{PEX_BINARY_OUTPUT}.  @var{outname} is interpreted as if

@code{PEX_LAST} were set.  On a successful return, @code{*@var{status}} will

be set to the exit status of the program.

@end deftypefn

@c pexecute.txh:228

@deftypefn Extension {FILE *} pex_read_err (struct pex_obj *@var{obj}, int @var{binary})

Returns a @code{FILE} pointer which may be used to read the standard

error of the last program in the pipeline.  When this is used,

@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After

this is called, @code{pex_run} may no longer be called with the same

@var{obj}.  @var{binary} should be non-zero if the file should be

opened in binary mode.  Don't call @code{fclose} on the returned file;

it will be closed by @code{pex_free}.

@end deftypefn

@c pexecute.txh:216

@deftypefn Extension {FILE *} pex_read_output (struct pex_obj *@var{obj}, int @var{binary})

Returns a @code{FILE} pointer which may be used to read the standard

output of the last program in the pipeline.  When this is used,

@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After

this is called, @code{pex_run} may no longer be called with the same

@var{obj}.  @var{binary} should be non-zero if the file should be

opened in binary mode.  Don't call @code{fclose} on the returned file;

it will be closed by @code{pex_free}.

@end deftypefn

@c pexecute.txh:33

@deftypefn Extension {const char *} pex_run (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{outname}, const char *@var{errname}, int *@var{err})

Execute one program in a pipeline.  On success this returns

@code{NULL}.  On failure it returns an error message, a statically

allocated string.

@var{obj} is returned by a previous call to @code{pex_init}.

@var{flags} is a bitwise combination of the following:

@table @code

@vindex PEX_LAST

@item PEX_LAST

This must be set on the last program in the pipeline.  In particular,

it should be set when executing a single program.  The standard output

of the program will be sent to @var{outname}, or, if @var{outname} is

@code{NULL}, to the standard output of the calling program.  Do @emph{not}

set this bit if you want to call @code{pex_read_output}

(described below).  After a call to @code{pex_run} with this bit set,

@var{pex_run} may no longer be called with the same @var{obj}.

@vindex PEX_SEARCH

@item PEX_SEARCH

Search for the program using the user's executable search path.

@vindex PEX_SUFFIX

@item PEX_SUFFIX

@var{outname} is a suffix.  See the description of @var{outname},

below.

@vindex PEX_STDERR_TO_STDOUT

@item PEX_STDERR_TO_STDOUT

Send the program's standard error to standard output, if possible.

@vindex PEX_BINARY_INPUT

@vindex PEX_BINARY_OUTPUT

@vindex PEX_BINARY_ERROR

@item PEX_BINARY_INPUT

@itemx PEX_BINARY_OUTPUT

@itemx PEX_BINARY_ERROR

The standard input (output or error) of the program should be read (written) in

binary mode rather than text mode.  These flags are ignored on systems

which do not distinguish binary mode and text mode, such as Unix.  For

proper behavior these flags should match appropriately---a call to

@code{pex_run} using @code{PEX_BINARY_OUTPUT} should be followed by a

call using @code{PEX_BINARY_INPUT}.

@vindex PEX_STDERR_TO_PIPE

@item PEX_STDERR_TO_PIPE

Send the program's standard error to a pipe, if possible.  This flag

cannot be specified together with @code{PEX_STDERR_TO_STDOUT}.  This

flag can be specified only on the last program in pipeline.

@end table

@var{executable} is the program to execute.  @var{argv} is the set of

arguments to pass to the program; normally @code{@var{argv}[0]} will

be a copy of @var{executable}.

@var{outname} is used to set the name of the file to use for standard

output.  There are two cases in which no output file will be used:

@enumerate

@item

if @code{PEX_LAST} is not set in @var{flags}, and @code{PEX_USE_PIPES}

was set in the call to @code{pex_init}, and the system supports pipes

@item

if @code{PEX_LAST} is set in @var{flags}, and @var{outname} is

@code{NULL}

@end enumerate

@noindent

Otherwise the code will use a file to hold standard

output.  If @code{PEX_LAST} is not set, this file is considered to be

a temporary file, and it will be removed when no longer needed, unless

@code{PEX_SAVE_TEMPS} was set in the call to @code{pex_init}.

There are two cases to consider when setting the name of the file to

hold standard output.

@enumerate

@item