4    Execution Environment Utilities


4.1    awk - Pattern scanning and processing language


4.1.5    External Influences


4.1.5.2    Input Files

[165:91] For these files (whether the variable RS is set to a value other than <newline> or not), the implementation shall support records terminated with the specified separator up to {LINE_MAX} bytes and may support longer records.

The operating system supports records up to 3,000 bytes long.


4.1.7    Extended Description


4.1.7.3    Variables and Special Variables

ENVIRON [171:344] In all cases where the behavior of awk is affected by environment variables [including the environment of any command(s) that awk executes via the system function or via pipeline redirections with the print statement, the printf statement, or the getline function], the environment used shall be the environment at the time awk began executing; it is implementation defined whether any modification of ENVIRON affects this environment.

Modification of ENVIRON has no effect on the awk interpretation of environment variables

SUBSEP [172:386] The subscript separator string for multidimensional arrays; the default value is implementation defined.

As the default value for SUBSEP, the operating system uses \031.


4.1.7.6    Actions


4.1.7.6.2    Functions .nr HF 0


4.1.7.6.2.3    Input/Output and General Functions .nr HF 0

close(expression) [179:679] The limit on the number of open expression arguments is implementation defined.

The operating system does not limit the number of open expression arguments, but there is a system limit of 4096 open files per process.


4.1.7.8    awk Lexical Conventions

[188:1101] If the size of a byte on the system is greater than 9 b, the valid escape sequence used to represent a byte is implementation defined.

The operating system does not recognize bytes greater than 9 b.


4.2    basename - Return nondirectory portion of pathname


4.2.2    Description

[190:1194] (1) If string is //, it is implementation defined whether steps (2) through (5) are skipped or processed.

If the argument string is the string "//", then steps (2) through (5) defined in the standard (page 190) are skipped by the operating system.


4.5    cd - Change working directory


4.5.2    Description

[207:1831] If HOME is empty or is undefined, the default behavior is implementation defined.

When HOME is empty or is undefined, the operating system does not change the current directory and outputs an error message.


4.5.4    Operands

directory [208:1840] If directory is -, the results are implementation defined.

When directory is -, the operating system changes the working directory to the directory name saved in the Environment Variable OLDPWD if it is not NULL. If OLDPWD is NULL, an error is reported.


4.5.5    External Influences


4.5.5.3    Environment Variables

HOME [208:1858] (Information not cited in POSIX.2.)

When HOME is empty or is undefined and directory was not specified, the operating system does not change the current directory and outputs an error.


4.7    chmod - Change file modes


4.7.2    Description

[212:1966] It is implementation defined whether and how the chmod utility affects any alternate or additional file access control mechanism (see file access permissions in [POSIX.2] 2.2.2.66) being used for the specified file.

On the operating system, the access control list (ACL) is an additional mechanism used to restrict access to files and directories. The chmod utility has no affect on the ACL.


4.7.7    Extended Description

[215:2064] When using the symbolic mode form on a regular file, it is implementation defined whether or not: .in +3m .nr IN +3m

Requests to set the set-user-ID-on-execution or set-group-ID-on-execution bit when all execute bits are being set are ignored,

Requests to clear all execute bits also clear the set-user-ID-on-execution and set-group-ID-on-execution bits, or

Requests to clear the set-user-ID-on-execution or set-group-ID-on-execution bits when all execute bits are currently clear are ignored. .in -3m .nr IN -3m

With the operating system when using the symbolic mode form on a regular file and all execute bits are being set, requests to set the set-user-ID-on-execution bit or the set-group-ID-on-execution bit are not ignored.

With the operating system when using the symbolic mode form on a regular file requests to clear all execute bits do not clear the set-user-ID-on-execution and set-group-ID-on-execution bits.

With the operating system when using the symbolic mode form on a regular file and all execute bits are currently clear, requests to clear the set-user-ID-on-execution bit or the set-group-ID-on-execution bit are not ignored.

[215:2076] When using the symbolic mode form on other (than regular) file types, it is implementation defined whether or not requests to set or clear the set-user-ID-on-execution or set-group-ID-on-execution bits are honored.

With the operating system when using the symbolic mode form on other than regular file types, requests to set the set-user-ID-on-execution bit or the set-group-ID-on-execution bit are honored.

With the operating system when using the symbolic mode form on other than regular file types, requests to clear the set-user-ID-on-execution bit or the set-group-ID-on-execution bit are honored.

[215:2089] For other (than regular) file types, it is implementation defined whether or not requests to set or clear the set-user-ID-on-execution or set-group-ID-on-execution bits are honored.

For other than regular file types, the operating system honors requests to set or clear the set-user-ID-on-execution bit or the set-group-ID-on-execution bit.


4.7.7.1    chmod Grammar

[216:2105] Implementations need not allow <blank>s within the single argument being processed.

The operating system does not allow <blank>s within the single argument being processed.


4.12    command - Execute a simple command


4.12.1    Synopsis

[228:2464] On systems supporting the User Portability Utilities Option, the following form also shall be supported.

The operating system supports the User Portability Utilities Option.


4.12.2    Description

[228:2475] On systems supporting the User Portability Utilities Option, the command utility also shall provide information concerning how a command name will be interpreted by the shell; see -v and -V.

The operating system supports the User Portability Utilities Option.


4.13    cp - Copy files


4.13.2    Description

[232:2621] If dest_file exists and it is a file type not specified by POSIX.1 {8}, the behavior is implementation defined.

The operating system does not recognize file types not specified by POSIX.1 {8}.

[234:2675] If the -r option was specified, the behavior is implementation defined.

If source_file is not of type directory or type regular file, does not reference the same file as dest_file, and the -r option was specified, then the operating system:

[234:2683] Otherwise, the permission, owner ID, and group ID of dest_file are implementation defined.

If source_file is a file of type FIFO, the -R option was specified, and the -p option was not specified, then the operating system sets the following for dest_file:

File permission bits Same as those of source_file modified by the file creation mask
Owner ID The effective user ID of the process
Group ID The group ID of the target directory of dest_file

[234:2688] If the implementation provides additional or alternate access control mechanisms (see [POSIX.2] 2.2.2.66), their effect on copies of files is implementation defined.

The operating system also provides an additional access control mechanism consisting of the access control list (ACL). The ACL can limit the ability of a process to use the cp utility on a file. If the ACL permits a process to copy a file, then the behavior is:

File permission bits Same as those of source_file modified by the file creation mask
Owner ID the effective user ID of the process
Group ID The group ID of the target directory of dest_file


4.13.3    Options

-p [234:2709] (3) Other implementation-defined bits may be duplicated as well.

If the -p option is specified, the operating system duplicates all the permission bits that are set in the source file.

-r [235:2721] The treatment of special files is implementation defined.

If the -r option is specified, the operating system opens special file types such as symbolic links, named pipes (FIFOs), and block and character devices, and copies their contents to regular files having the same name.


4.18    dirname - Return directory portion of pathname


4.18.2    Description

[255:3405] (6) If the remaining string is //, it is implementation-defined whether steps (7) and (8) are skipped or processed.

When a remaining string, after applying the rules for stripping characters, is //, the operating system performs the processing specified in steps (7) and (8) of the standard. The resulting string is a single slash character written to standard output.


4.19    echo - Write arguments to standard output


4.19.4    Operands

string [257:3468] If the first operand is "-n" or if any of the operands contain a backslash (\) character the results are implementation defined.

In the POSIX environment, an operand of "-n" has no special meaning. The operating system treats the operand as another string.

The operating system treats a backslash (\) character as an escape character unless it is enclosed in quotation marks.


4.20    ed - Edit text


4.20.7    Extended Description


4.20.7.3    ed Commands


4.20.7.3.14    List Command .nr HF 0

[267:3828] If the size of a byte on the system is greater than 9 b, the format used for nonprintable characters is implementation defined.

The operating system does not recognize bytes of a size greater than 9 b.


4.24    find - Find files


4.24.4    Operands

[280:4277] If a utility_name or argument string contains the two characters {}, but not just the two characters {}, it is implementation defined whether find replaces these two characters with the current pathname or uses the string without change.

If a utility_name or argument string contains the two characters {}, but not just the two characters {}, for the operating system, find uses the string without change.


4.26    getconf - Get configuration values


4.26.4    Operands

system_var [288:4563] The implementation may support additional system_var operand values.

The operating system accepts the following additional values for the system_var operand, with the meanings indicated;

ATEXIT_MAX The maximum number of functions that can be registered with atexit() per process.
CHARCLASS_NAME_MAX The maximum number of bytes in a character class name.
CHAR_BIT Number of bits in a type char.
CHAR_MAX The maximum value of a type char.
CHAR_MIN The minimum value of a type char.
CS_PATH A value for the PATH environment variable that finds all standard utilities.
DATAKEYS_MAX The maximum number of data keys that may be created per process.
INT_MAX The maximum value of an int.
INT_MIN The minimum value of an int.
LONG_BIT Number of bits in a long int.
LONG_MAX The maximum value of a long int.
LONG_MIN The minimum value of a long int.
MB_LEN_MAX The maximum number of bytes in a character for any supported locale.
NL_ARGMAX The maximum value of digit in calls to the printf() and scanf() functions.
NL_LANGMAX The maximum number of bytes in a LANG name.
NL_MSGMAX The maximum message number.
NL_NMAX The maximum number of bytes in an N-to-1 collation mapping.
NL_SETMAX The maximum set number.
NL_TEXTMAX The maximum number of bytes in a message string.
NZERO Default process priority.
PAGE_SIZE The page size granularity for memory regions.
PASS_MAX The maximum number of characters returned by getpass() (not including terminating null).
PATH A value for the PATH environment variable that finds all standard utilities.
SCHAR_MAX The maximum value of a type signed char.
SCHAR_MIN The minimum value of a type signed char.
SHRT_MAX The maximum value of a type short.
SHRT_MIN The minimum value of a type short.
TMP_MAX The minimum number of unique pathnames generated by tmpnam(). Maximum number of times an application can call tmpnam() reliably.
UCHAR_MAX The maximum value of a type unsigned char.
UINT_MAX The maximum value of a type unsigned int.
ULONG_MAX The maximum value of a type unsigned long int.
USHRT_MAX The maximum value of a type unsigned short int.
WORD_BIT Number of bits in a word or type int.
_AES_OS_VERSION The integer value indicating the revision of the Application Environment Specification to which the implementation is compliant.
_POSIX_LOCALEDEF This variable has a value of 1 if the system restricts supported locales to only those it supplies; otherwise, the variable has a value of 0 (zero).
_POSIX_REENTRANT_FUNCTIONS This variable has a value of 1 if the system supports POSIX reentrant functions; otherwise, the variable is undefined.
_POSIX_THREAD_ATTR_STACKSIZE This variable has a value of 1 if the system supports the POSIX threads stack size attribute; otherwise, the variable is undefined.
_POSIX_THREADS This variable has a value of 1 if the system supports POSIX threads; otherwise, the variable is undefined.
POSIX2_C_VERSION The integer value 199209L. This value indicates the version of the interfaces described in the C-Language Bindings Option section of the XPG4 standard. This value changes with each published version of ISO/IEC 9945 to indicate the 4-digit year and 2-digit month that the standard was approved by the IEEE Standards Board.
POSIX2_FORT_RUN This variable has a value of 1 if the system supports the FORTRAN Runtime Utilities Option from POSIX.2; otherwise, the variable is undefined.
SSIZE_MAX The maximum value that can be stored in an object of type ssize_t.
_XOPEN_CRYPT To have a value other than -1 if the implementation supports the X/Open Encryption Feature Group.
_XOPEN_ENH_I18N To have a value other than -1 if the implementation supports the X/Open Enhanced Internationalization Feature Group.
_XOPEN_SHM To have a value other than -1 if the implementation supports the X/Open Shared Memory Feature Group.
_XOPEN_VERSION An integer indicating the most current version of the X/Open standard that the system supports.
_XOPEN_XCU_VERSION An integer value indicating the version of the XCU specification to which the implementation conforms. If the value is -1, no commands and utilities are provided on the implementation.
_XOPEN_XPG2 It is defined only if the implementation supports the X/Open Portability Guide, Volume2, January 1987, XVS System Calls and Libraries.
_XOPEN_XPG3 It is defined only if the implementation supports the X/Open Specification, February 1992, System Interfaces and Headers, Issue 3.
_XOPEN_XPG4 It is defined only if the implementation supports the X/Open CAE Specification, July 1992, Systems Interfaces and Headers, Issue 4.
path_var [289:4571] The implementation may support additional path_var operand values.

The operating system accepts no other values for path_var.


4.32    kill - Terminate or signal processes


4.32.4    Operands

pid [311:5288] (2) On systems supporting both the POSIX.1 {8} job control option and the User Portability Utilities Option, a job control ID (see [POSIX.2] 2.2.2.94) that identifies a background process group to be signaled.

The operating system supports both the POSIX.1 {8} job control option and the User Portability Utilities Option.


4.33    ln - Link files


4.33.2    Description

[313:5357] If the last operand specifies an existing file of a type not specified by POSIX.1 {8}, the behavior is implementation defined.

The operating system does not support file types not specified by POSIX.1 {8}.


4.33.4    Operands

source_file [314:5384] This can be a regular file or special file; whether a directory can be linked is implementation defined.

The operating system allows a directory to be linked.


4.34    locale - Get locale-specific information


4.34.3    Options

-a [316:5450] The manner in which the implementation determines what other locales are available is implementation defined.

For the operating system, the command locale -a determines available locales by searching the path specified by the LOCPATH environment variable. The default is /usr/lib/nls/loc.


4.34.4    Operands

name [316:5464] It is implementation defined whether any keyword values are written for the categories LC_CTYPE and LC_COLLATE.

The operating system writes keyword values for category LC_CTYPE.

The operating system does not write keyword values for category LC_COLLATE.


4.35    localedef - Define locale environment


4.35.2    Description

[320:5573] It is implementation defined whether users shall have the capability to create new locales, in addition to those supplied by the implementation.

The operating system allows users to create additional locales.

[320:5584] Implementations may restrict the capability to create or modify public locales to users with appropriate privileges.

With the operating system, only a superuser may modify a public locale. A private user cannot create a public locale, but a locale created by a private user may later be moved to a public area by a user with superuser privileges.

[320:5588] In addition, the input may contain source for implementation-defined categories.

The operating system does not support any additional categories.

-f charmap [321:5611] If the -f option is not present, an implementation-defined character mapping shall be used.

If the -f option is not present, the operating system uses the Portable Character Set (PCS).


4.35.4    Operands

name [321:5622] If name does not contain any slash characters, the interpretation of the name is implementation defined, and the locale shall be public.

If name does not contain any slash characters, the operating system stores the created locale definition in the current working directory.

name [321:5624] This capability may be restricted to users with appropriate privileges.

The operating system restricts the users capability to modify or create public locales to superusers. However, a locale created by a private user may later be moved to a public area by a superuser.


4.35.9    Consequences of Errors

[323:5691] Other implementation-defined conditions may also cause warnings.

The operating system does not recognize any other conditions to cause warnings.


4.36    logger - Log messages


4.36.2    Description

[324:5699] It is implementation defined whether messages written in locales other than the POSIX Locale are effective.

The operating system recognizes messages written in all locales.


4.39    ls - List directory contents


4.39.3    Options

-a [331:5912] Entries beginning with a period (.) shall not be written out unless they are explicitly referenced, the -a option is supplied, or any implementation-defined condition causes them to be written.

The operating system also writes out entries beginning with a period (.) when the implementation defined -A option is used. In this case the special entries dot (.) and dot dot (..) are suppressed.

-R [331:5910] [This section should have the same caveat as the -d option.]

If the -d and -R options are both used, the operating system ignores the -R option.


4.39.5    External Influences


4.39.5.3    Environment Variables

COLUMNS [332:5955] If COLUMNS is not set or is invalid, an implementation-defined number of column positions shall be assumed, based on the knowledge of the output device by the implementation.

If COLUMNS is not set or is invalid, the operating system uses ioctl() to determine the number of byte positions in the output line. If ls cannot get this information, it uses a default value of 80. Columns may not be smaller than 20 bytes or larger than 400 bytes.


4.39.6    External Effects


4.39.6.1    Standard Output

[333:5989] If the output is to a terminal, the format is implementation defined.

If the output is to a terminal and no formatting options are specified, the operating system lists the files horizontally. When the width of the terminal display prevents a complete filename from being written, a new line is started. If the filelist is more than one line, filenames are aligned in columns.

[334:6015] If the file is a character special or block special file, the size of the file may be replaced with implementation-defined information associated with the device in question.

If the file is a character special or block special file, the operating system replaces the size of the file with the major and minor device numbers.

[334:6031] Implementations may add other characters to this list to represent other, implementation-defined, file types.

The operating system also uses the following characters and file types:

l symbolic link
s local socket

[335:6049] Implementations may add other characters to this list for the third character position.

The operating system also uses t or T if the 01000 (octal) bit of the mode is set.


4.40    mailx - Process messages


4.40.1    Synopsis

[336:6079] On systems supporting the User Portability Utilities Option, the following forms also shall be valid (Receive Mode):

The operating system supports the User Portability Utilities Option.


4.40.3    Options

[337:6113] The other options are required only on systems supporting the User Portability Utilities Option.

The operating system supports the User Portability Utilities Option.


4.40.7    Extended Description

342:6305] The entire Extended Description subclause ([POSIX.2] 4.40.7 through [POSIX.2] 4.40.7.3) shall apply only to implementations supporting the User Portability Utilities Option.

The operating system supports the User Portability Utilities Option.


4.40.7.1    mailx Internal Variables

crt=number [345:6453] If it is set to null, the value used is implementation defined.

If crt is not set, the operating system does not pipe messages through the command specified by PAGER.


4.40.7.3    mailx Command Escapes

~h [356:6871] Other implementation-defined headers may also be presented for editing.

The operating system presents no other headers for editing.


4.43    mv - Move files


4.43.2    Description

[363:7084] If any operand specifies an existing file of a type not specified by POSIX.1 {8}, the behavior is implementation defined.

The operating system does not use files not specified by POSIX.1 {8}.


4.45    od - Dump files in various formats


4.45.7    Extended Description

[372:7389] If the c89 compiler is present on the system, these specifiers correspond to the sizes used by default in that compiler. Otherwise these sizes are implementation defined.

The operating system assumes the c89 compiler is always present.

[372:7398] The byte order used when interpreting numeric values is implementation defined, but shall correspond to the order in which a constant of the corresponding type is stored in memory on the system.

The operating system on Alpha machines represents byte order least-significant byte first.

[373:7431] If the size of a byte on the system is greater than 9 b, the format used for nonprintable characters is implementation defined.

The operating system does not use bytes greater than 9 b.

[373:7436] When either the -j skip or -N count option is specified along with the c type specifier, and this results in an attempt to start or finish in the middle of a multibyte character, the result is implementation defined.

If use of the -j skip option or -N count option, or both, along with the c type specifier results in an attempt to start in the middle of a multibyte character:

  1. If the incomplete multibyte character forms a valid multibyte character by itself, then the operating system prints that multibyte character.

  2. If the incomplete multibyte character does not form a valid multibyte character, then the operating system dumps out the hex value, and tries to continue parsing the multibyte string.

If use of the -j skip option or -N count option, or both, along with the c type specifier results in an attempt to finish in the middle of a multibyte character:

  1. If the incomplete multibyte character forms a valid multibyte character by itself, then the operating system prints that multibyte character.

  2. If the incomplete multibyte character does not form a valid multibyte character, the operating system dumps the hex value.


4.48    pax - Portable archive interchange


4.48.2    Description

copy [381:7687] If the destination directory is a file of a type not defined by POSIX.1 {8}, the results are implementation defined; otherwise it shall be an error for the file named by the directory operand not to exist, not to be writable by the user, or not to be a file of type directory.

The operating system does not recognize file types not specified by POSIX.1 {8}.

[381:7701] The default output archive format shall be implementation defined.

For the operating system, the default output archive format is the extended tar interchange (ustar) format.

[381:7703] The pax utility shall determine, in an implementation-defined manner, what file to read or write as the next file.

The operating system determines the next file to read by proceeding linearly through the file list presented.

The operating system determines the next file to write by proceeding linearly through the archive contents.


4.48.3    Options

-a [381:7715] It is implementation defined which devices on the system support appending.

The operating system does not support file formats not specified by POSIX.1 {8}.

-p string [382:7767] The string shall consist of the specification characters a, e, m, o, and p, and/or other implementation-defined characters.

The operating system recognizes no other specification characters.

-p string The meanings of the specification characters are as follows:
  e [383:7774] Preserve the user ID, group ID, file mode bits (see [POSIX.2] 2.2.2.7.1), access time, modification time, and any other implementation-defined file characteristics.

The operating system preserves no other file characteristics.

-p string The meanings of the specification characters are as follows:
  p [383:7779] Other, implementation-defined file-mode attributes may be preserved.

The operating system also preserves the file access permission.

-x format [384:7846] Implementation-defined formats shall specify a default block size as well as any other block size supported for character special archive files.

The operating system supports no other formats.

The operating system supports no other block size for character special archive files.


4.48.5    External Influences


4.48.5.2    Input Files

[385:7885] The input file named by the archive option-argument, or standard input when the archive is read from there, shall be a file formatted according to one of the specifications in Section 10.1 of POSIX.1 {8}, or some other implementation-defined format.

The operating system does not use file types not specified by POSIX.1 {8}.


4.48.6    External Effects


4.48.6.1    Standard Output

[386:7920] In write mode, if -f is not specified, the standard output shall be the archive formatted according to one of the specifications in Section 10.1 of POSIX.1 {8}, or some other implementation-defined format. (See -x format under [POSIX.2] 4.48.3).

The operating system produces no other output file formats.


4.48.6.3    Output Files

[387:7957] In write mode, the output file named by the -f option argument shall be a file formatted according to one of the specifications in Section 10.1 of POSIX.1 {8}, or some other implementation-defined format.

The operating system produces no other output file formats.


4.50    printf - Write formatted output


4.50.7    Extended Description

[395:8209] (6) The e, E, f, g, and G conversion specifications need not be supported.

The operating system supports the e, E, f, g, and G conversion specifications.


4.55    sed - Stream editor


4.55.7    Extended Description


4.55.7.3    sed Editing Commands

[410:8677] The r and w commands take an optional rfile (or wfile) parameter, separated from the command letter by one or more <blank>s; implementations may allow zero separation as an extension.

The operating system does not allow zero separation.

[1addr]l (The letter ell.)
  [411:8732] If the size of a byte on the system is greater than 9 b, the format used for nonprintable characters is implementation defined.

The operating system does not use bytes greater than 9 b.


4.56    sh - Shell, the standard command language interpreter


4.56.3    Options

[414:8837] The -b, -m, and -o option options need not be supported on systems not supporting the User Portability Utilities Option.

The operating system supports the User Portability Utilities Option.


4.56.5    External Influences


4.56.5.3    Environment Variables

PS1 [418:9029] For users who have specific additional implementation-defined privileges (see [POSIX.2] 2.2.2.8), the default may be another implementation defined value.

The operating system provides a # as the default value for PS1 for users with super-user privileges.


4.62    test - Evaluate expression


4.62.4    Operands

[451:10226] Additional implementation-defined operators and primary_operators may be provided by implementations.

The operating system provides the following additional operators:

-h file True if file exists and is a soft link. Synonym for -L expression.
-L file True if file exists and is a soft link. Synonym for -h expression.
-k file True if file exists and its sticky bit is set.
primary -a primary Performs a binary and of the results of primary and primary. The -a operator has precedence over the -o operator.
primary -o primary Performs a binary or of the results of primary and primary. The -a operator has precedence over the -o operator.

[451:10228] The additional implementation-defined operators "(" and ")" may also be provided by implementations.

The operating system does not provide the "(" and ")" operators. The operating system provides the "\(" and "\)" operators for grouping elements in an expression.


4.63    touch - Change file access and modification times


4.63.3    Options

[455:10348] The range of valid times past the Epoch is implementation defined, but it shall extend to at least midnight 1 January 2000 UTC.

The operating system supports a range of valid times past Epoch that extends to Tuesday, January 19, 2038 at 03:14:07 UTC.


4.64    tr - Translate characters


4.64.7    Extended Description

\octal [460:10488] If the size of a byte on the system is greater than 9 b, the valid escape sequence used to represent a byte is implementation defined.

The operating system does not use bytes greater than 9 b.


4.68    uname - Return system name


4.68.2    Description

[469:10778] The format and contents of the symbols are implementation defined.

The operating system conforms to POSIX.1 {8} and writes the symbols supported by the POSIX.1 {8} uname() function. The format of the output is the applicable portion(s) of the output format specified in POSIX.2 4.68.6.1.


4.68.6    External Effects


4.68.6.1    Standard Output

[471:10829] Additional implementation-defined symbols may be written; all such symbols shall be written at the end of the line of output before the <newline>.

The operating system writes no additional symbols to the standard output.


4.70    wait - Await process completion


4.70.4    Operands

pid [475:10957] (2) On systems supporting both the POSIX.1 {8} job control option and the User Portability Utilities Option, a job control ID (see [POSIX.2] 2.2.2.94) that identifies a background process group to be waited for.

The operating system supports both the POSIX.1 {8} job control option and the User Portability Utilities Option.