NAME

SYNOPSIS

DESCRIPTION

The sfind utility is able to descend to arbitrary depths in a file hierarchy and does not fail due to path length limitations (unless a path operand specified by the application exceeds PATH_MAX requirements).

The sfind utility detects infinite loops; that is, entering a previously visited directory that is an ancestor of the last file encountered. When it detects an infinite loop, sfind does not write a diagnostic message to standard error (the POSIX standards likes find to write this message) and either recovers its position in the hierarchy or terminates.

OPTIONS

The IEEE Std 1003.1-2001 standard requires the options -H and -L to be supported. All other sfind options are local extensions.

-H

Cause the file information and file type evaluated for each symbolic link encountered on the command line to be those of the file referenced by the link, and not the link itself. If the referenced file does not exist, the file information and type is for the link itself. File information for all symbolic links not on the command line is that of the link itself.

-L

Cause the file information and file type evaluated for each symbolic link to be those of the file referenced by the link, and not the link itself.

-P

Cause the file information and file type evaluated for each symbolic link to be those of the link itself. The sfind utility will not follow symbolic links at any part of the file hierarchy. This is the default.

Specifying more than one of the mutually-exclusive options -H, -L and -P is not considered an error. The last option specified determines the behavior of the utility.

-help

Prints a short summary of the sfind options and exists.

-version

Prints the sfind version number string and exists.

OPERANDS

path

The path operand is a pathname of a starting point in the directory hierarchy.

operand_expression

The first argument that starts with a '-', or is a '!' or a '(', and all subsequent arguments are interpreted as an expression made up of the following primaries and operators. In the descriptions, wherever n is used as a primary argument, it is interpreted as a decimal integer optionally preceded by a plus ('+') or minus ('-') sign, as follows:

The following logical operators are supported:

( )

Group an expression

!

Logical NOT

-a

Logical AND

-o

Logical OR

The following primaries are supported:

-acl

The primary evaluates as true if the file has additional ACLs defined. On platforms that do not support ACLs or where sfind does not yet support ACLs, the primary always evaluates as false. Currently only Solaris, Linux and FreeBSD is supported.

This primary is not mentioned in the POSIX standard.

-amin n

The parameter n must be a simple number that is evaluated as minutes for the file access time relatively to the start time of sfind.

This primary is deprecated and only exists for command line compatibility with other find implementations. Please use the more flexible -atime instead.

This primary is not mentioned in the POSIX standard.

-atime n

If n is a simple number, the primary evaluates as true if the file access time subtracted from the initialization time, divided by 86400 (with any remainder discarded), is n.

If n is a number like 3h10m then it is representing an absolute number in seconds that is evaluated against the start time of sfind. The letters that are recognised in the time spec are taken from smhdwy.

-call command [argument ...] \;

-calldir command [argument ...] \;

These primaries are similar to -exec and -execdir but the command is called by a callback into the caller of the library and not by creating a new process.

In the Bourne Shell, the command is evaluated similar to the eval(1) command in case it does not contain a shell variable reference and similar to sh -c command call argument... in case there is a variable reference.

This primary is only available in the library version of sfind(1) (libfind).

This primary is not mentioned in the POSIX standard.

-chatime timespec

This primary modifies the time of last access of a file in struct stat. This primary always evaluates to true. See -newerXY below for a description of timespec.

This primary is not mentioned in the POSIX standard.

-chctime timespec

This primary modifies the time of last status change of a file in struct stat. This primary always evaluates to true. See -newerXY below for a description of timespec.

This primary is not mentioned in the POSIX standard.

-chmtime timespec

This primary modifies the time of last modification of a file in struct stat. This primary always evaluates to true. See -newerXY below for a description of timespec.

This primary is not mentioned in the POSIX standard.

-chown uname

-chown uid

This primary modifies the owner of a file in struct stat. This primary always evaluates to true.

This primary is not mentioned in the POSIX standard.

-chgrp gname

-chgrp gid

This primary modifies the group of a file in struct stat. This primary always evaluates to true.

This primary is not mentioned in the POSIX standard.

-chmod mode

This primary modifies the permissions of a file in struct stat. The mode parameter may use the same syntax as in the chmod(1) command. This primary always evaluates to true.

This primary is not mentioned in the POSIX standard.

-chfile

If a previous primary -chatime, -chctime, -chmtime, -chown, -chgrp or -chmod modified elements in struct stat, the modified values are set on the file.

On platforms where chmod(2) is not possible on symbolic links, symbolic links are skipped. On platforms where is not possible to set time stamps on symbolic links, symbolic links are skipped.

If setting the new values does not work, this primary evaluates to false.

This primary is not mentioned in the POSIX standard.

-cmin n

The parameter n must be a simple number that is evaluated as minutes for the last change of file status information relatively to the start time of sfind.

This primary is deprecated and only exists for command line compatibility with other find implementations. Please use the more flexible -ctime instead.

This primary is not mentioned in the POSIX standard.

-ctime n

If n is a simple number, the primary evaluates as true if the time of last change of file status information subtracted from the initialization time, divided by 86400 (with any remainder discarded), is n.

If n is a number like 3h10m then it is representing an absolute number in seconds that is evaluated against the start time of sfind. The letters that are recognised in the time spec are taken from smhdwy.

-depth

The primary always evaluates as true; it causes the descent of the directory hierarchy to be done so that all entries in a directory are acted on before the directory itself. If a -depth primary is not specified, all entries in a directory are acted on after the directory itself. If any -depth primary is specified, it applies to the entire expression even if the -depth primary would not normally be evaluated.

-dostat

Call stat(2) or lstat(2) for every file, do not try to do stat(2) optimization.

By default, sfind tries to avoid stat(2) calls in case that the expression does not need to reference fields from struct stat and the file system is known to behave like classical UNIX filesystems. Stat(2) optimization is done by assuming that the number of subdirectories is st_nlink - 2 and gives a significant increase in search speed in case that only filename related expressions are used.

This primary is not mentioned in the POSIX standard.

-empty

This primary evaluates true if the current file is a readable empty directory or an empty plain file.

This primary is not mentioned in the POSIX standard.

-exec utility_name [argument ...] \;

-exec utility_name [argument ...] {} +

The end of the primary expression must be punctuated by a semicolon or by a plus sign. Only a plus sign that follows an argument containing the two characters "{}" punctuates the end of the primary expression. Other uses of the plus sign are not treated as special.

If the primary expression is punctuated by a semicolon, the utility utility_name is be invoked once for each pathname and the primary evaluates as true if the utility returns a zero value as exit status. A utility_name or argument containing only the two characters "{}" is replaced by the current pathname.

If the primary expression is punctuated by a plus sign, the primary always evaluates as true, and the pathnames for which the primary is evaluated is aggregated into sets. The utility utility_name is invoked once for each set of aggregated pathnames. Each invocation begins after the last pathname in the set is aggregated, and is completed before the sfind utility exits and before the first pathname in the next set (if any) is aggregated for this primary, but it is otherwise unspecified whether the invocation occurs before, during, or after the evaluations of other primaries. If any invocation returns a non-zero value as exit status, the sfind utility returns a non-zero exit status. An argument containing only the two characters "{}" is replaced by the set of aggregated pathnames, with each pathname passed as a separate argument to the invoked utility in the same order that it was aggregated. The size of any set of two or more pathnames is limited such that execution of the utility does not cause the system's ARG_MAX limit to be exceeded. The sfind utility reserves LINE_MAX in the execution environment for the called utility to allow this utility to modify its environment and call further programs recursively. This results in a maximum argument space of ARG_MAX-LINE_MAX that is used by sfind. If more than one argument containing only the two characters "{}" is present, the behavior is unspecified. The sfind implementation only expands the last "{}" argument that directly prepends the '+' argument.

If a utility_name or argument string contains the two characters "{}" , but not just the two characters "{}" , it is implementation-defined whether find replaces those two characters or uses the string without change. The sfind implementation only expands arguments that are exactly the two characters "{}". The current directory for the invocation of utility_name is the same as the current directory when the sfind utility was started. If the utility_name names any of the special built-in utilities (see Special Built-In Utilities ), the results are undefined.

-execdir utility_name [argument ...] \;

Similar to -exec but the utility is run inside the directory where the file is found and the file parameter is provided as a short file name.

This primary is not mentioned in the POSIX standard.

-executable

This primary evaluates as true if the file is executable by the real user id of the sfind process. The test is done by calling access(2).

This primary is not mentioned in the POSIX standard.

-false

This primary always evaluates to false.

This primary is not mentioned in the POSIX standard.

-fls file

This primary is similar to -ls but it writes the output into file, similar to -fprint.

This primary is not mentioned in the POSIX standard.

-follow

The primary always evaluates as true; it causes sfind to follow all symbolic links. While symbolic links that do not point to valid files, are evaluated as symbolic links when -H or -L is used, using -follow causes sfind to write a diagnostic message and to skip the symbolic link in this case.

This primary is not mentioned in the POSIX standard.

-fprint file

This primary is similar to -print but it writes the output into file. If file does not exist, it is created, if it already exists, it is truncated. The file is written to in append mode. it is always created, even if the primary was never called.

This primary is not mentioned in the POSIX standard.

-fprint0 file

This primary is similar to -print0 but it writes the output into file, similar to -fprint.

This primary is not mentioned in the POSIX standard.

-fprintnnl file

This primary is similar to -printnnl but it writes the output into file, similar to -fprint.

This primary is not mentioned in the POSIX standard.

-fstype type

The primary evaluates as true if the file belongs to a filesystem of type type. This is currently done by comparing st_fstype with type.

This primary is not mentioned in the POSIX standard.

-group gname

-group gid

The primary evaluates as true if the file belongs to the group gname. If gname is a decimal integer and the getgrnam() (or equivalent) function does not return a valid group name, gname is interpreted as a group ID.

-ilname glob

Similar to -lname, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-ilpat pattern

Similar to -lpat, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-iname glob

Similar to -name, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-inum #

The primary evaluates as true if the file's inode number (st_ino) matches #.

This primary is not mentioned in the POSIX standard.

-ipat pattern

Similar to -pat, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-ipath glob

Similar to -path, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-ippat pattern

Similar to -ppat, but the match is case insensitive.

This primary is not mentioned in the POSIX standard.

-linkedto path

The primary evaluates as true if the file is liked to path (i.e. evaluates to the same physical file). This primary is similar to the -inum primary, but it evaluates st_dev and st_ino and thus correctly detects hard linked files even when multiple file systems are searched.

This primary is not mentioned in the POSIX standard.

-links #

The primary evaluates as true if the file has # links.

-lname glob

The primary evaluates as true if the symbolic link target name of the filename being examined matches glob using the pattern matching notation described in Pattern Matching Notation (see fnmatch(2) for more information).

This primary is not mentioned in the POSIX standard.

-local

The primary evaluates as true if st_fstype does not match remote fs types.

This primary is not mentioned in the POSIX standard.

-lpat pattern

The primary evaluates as true if the symbolic link target name of the filename being examined matches pattern using the pattern matching notation described in patcompile(3), patmatch(3) and match(1).

This primary is not mentioned in the POSIX standard.

-ls

This primary always evaluates to true. It causes sfind to list information for the current file to standard output: its inode number, size in 1024-byte blocks, file permissions, number of hard links, owner, group, size in bytes, last modification time, and pathname. If the file is a block or character special file, the major and minor numbers will be displayed instead of the size in bytes. If the file is a symbolic link, the pathname of the linked-to file will be displayed preceded by ``->''. The format is identical to that produced by 'ls -ilds'.

This primary is not mentioned in the POSIX standard.

-maxdepth #

The primary always evaluates as true; descend at most # directory levels below the command line arguments. If any -maxdepth primary is specified, it applies to the entire expression even if it would not normally be evaluated. -maxdepth 0 limits the whole search to the command line arguments.

This primary is not mentioned in the POSIX standard.

-mindepth #

The primary always evaluates as true; do not apply any tests or actions at levels less than #. If any -mindepth primary is specified, it applies to the entire expression even if it would not normally be evaluated. -mindepth 1 processes all but the command line arguments.

This primary is not mentioned in the POSIX standard.

-mount

The primary always evaluates as true; it causes sfind not to report files and not to descent into directories that have a different device ID (st_dev, see the stat() function defined in the System Interfaces volume of IEEE Std 1003.1-2001). If any -mount primary is specified, it applies to the entire expression even if the -mount primary would not normally be evaluated.

The -mount primary exists for backwards compatibility with old UNIX find(1) versions and has been added to POSIX with issue 8.

If both -mount and -mount+ or -xdev have been specified, -mount wins.

-mount+

The primary always evaluates as true; it causes sfind to report directories but not to continue descending past directories that have a different device ID (st_dev, see the stat() function defined in the System Interfaces volume of IEEE Std 1003.1-2001). If any -mount+ primary is specified, it applies to the entire expression even if the -mount+ primary would not normally be evaluated.

This primary is not mentioned in the POSIX standard, but the POSIX -xdev primary is an alias to -mount+.

-mmin n

The parameter n must be a simple number that is evaluated as minutes for the file modification time relatively to the start time of sfind.

This primary is deprecated and only exists for command line compatibility with other find implementations. Please use the more flexible -mtime instead.

This primary is not mentioned in the POSIX standard.

-mtime n

If n is a simple number, the primary evaluates as true if the file modification time subtracted from the initialization time, divided by 86400 (with any remainder discarded), is n.

If n is a number like 3h10m then it is representing an absolute number in seconds that is evaluated against the start time of sfind. The letters that are recognised in the time spec are taken from smhdwy with the following meaning for time units:

-name glob

The primary evaluates as true if the basename of the filename being examined matches glob using the pattern matching notation described in Pattern Matching Notation (see fnmatch(2) for more information).

-newer file

The primary evaluates as true if the modification time of the current file is more recent than the modification time of the file named by the pathname file.

-newerXY file

The primary evaluates as true if the time referred to by X of the current file is more recent than the time referred to by Y of the file named by the pathname file. The time type indicators X and Y may be one of:

-nogroup

The primary evaluates as true if the file belongs to a group ID for which the getgrgid() function defined in the System Interfaces volume of IEEE Std 1003.1-2001 (or equivalent) returns NULL.

-nouser

The primary evaluates as true if the file belongs to a user ID for which the getpwuid() function defined in the System Interfaces volume of IEEE Std 1003.1-2001 (or equivalent) returns NULL.

-ok utility_name [argument ...] \;

The -ok primary is equivalent to -exec, except that the use of a plus sign to punctuate the end of the primary expression need not be supported (in fact, sfind does not support it), and sfind will request affirmation of the invocation of utility_name using the current file as an argument by writing to standard error as described in the STDERR section. If the response on standard input is affirmative, the utility is invoked. Otherwise, the command is not invoked and the value of the -ok operand is false.

-okdir utility_name [argument ...] \;

Similar to -ok but the utility is run inside the directory where the file is found and the file parameter is provided as a short file name.

This primary is not mentioned in the POSIX standard.

-pat pattern

The primary evaluates as true if the basename of the filename being examined matches pattern using the pattern matching notation described in patcompile(3), patmatch(3) and match(1).

This primary is not mentioned in the POSIX standard.

-path glob

The primary evaluates as true if the full path name of the filename being examined matches glob using the pattern matching notation described in Pattern Matching Notation (see fnmatch(2) for more information).

This primary is not mentioned in the POSIX standard.

-perm [-]mode

The mode argument is used to represent file mode bits. It is identical in format to the symbolic_mode operand described in chmod(), and is interpreted as follows. To start, a template is assumed with all file mode bits cleared. An op symbol of '+' sets the appropriate mode bits in the template; '-' clears the appropriate bits; '=' sets the appropriate mode bits, without regard to the contents of process' file mode creation mask. The op symbol of '-' cannot be the first character of mode; this avoids ambiguity with the optional leading hyphen. Since the initial mode is all bits off, there are not any symbolic modes that need to use '-' as the first character.

If the hyphen is omitted, the primary evaluates as true when the file permission bits exactly match the value of the resulting template.

Otherwise, if mode is prefixed by a hyphen, the primary evaluates as true if at least all the bits in the resulting template are set in the file permission bits.

-perm +mode

This usage of the primary -perm evaluates as true if any of the permission bits mode are set for the file. The specific interpretation when testing whether any of the mode bits are set for the file applies only to those symbolic mode strings that cannot have a leading '+' in a POSIX compliant way. This is the case when the '+' is directly preceding the character: 'a'. Because of this limitation, the otherwise correct symbolic mode +x could be written as a+x and then preceded by '+' resulting in +a+x. This is required because the mode string ++x is still POSIXly correct syntax and there is no way to detect that the first '+' is indicating a usage specific to the sfind -perm primary. The strings '+u', '+g', '+o' indicate a so called permcopy operation and as a result, most legal symbolic mode strings do not become illegal by prefixing them with a '+'.

Since the start value used by the permission parser for the find(1) -perm primary is always zero, any POSIXly valid symbolic mode string may be prefixed by 'a+,' without changing the resulting value, prefixing any mode string with '+a+,' makes it a recognized value for this usage of the -perm primary.

Note that libfind versions before 1.7 permitted the mode string to start with 'u', 'g', 'o' for the -perm +mode feature and thus might have been in conflict with POSIX.

This usage of the primary -perm is not mentioned in the POSIX standard.

-perm /mode

This is an alias for -perm +mode but since '/' is not part of the POSIX standard for the symbolic mode, there is no need to prefix the symbolic mode with 'a+,' to make it work in case the symbolic notation does not start with 'a'.

This usage of the primary -perm is not mentioned in the POSIX standard.

-perm [-]onum

If the hyphen is omitted, the primary evaluates as true when the file permission bits exactly match the value of the octal number onum and only the bits corresponding to the octal mask 07777 is compared. (See the description of the octal mode in chmod() .) Otherwise, if onum is prefixed by a hyphen, the primary evaluates as true if at least all of the bits specified in onum that are also set in the octal mask 07777 are set.

-perm +onum

This usage of the primary -perm evaluates as true if any of the mode bits in the octal notation onum are set for the file.

This usage of the primary -perm is not mentioned in the POSIX standard.

-perm /onum

This is an alias for -perm +onum and supported for compatibility reasons.

This usage of the primary -perm is not mentioned in the POSIX standard.

-ppat pattern

The primary evaluates as true if the full path name of the filename being examined matches pattern using the pattern matching notation described in patcompile(3), patmatch(3) and match(1).

This primary is not mentioned in the POSIX standard.

-print

The primary always evaluates as true; it causes the current pathname (new line separated) to be written to standard output.

-print0

The primary always evaluates as true; it causes the current pathname (nul separated) to be written to standard output.

This primary is not mentioned in the POSIX standard.

-printnnl

The primary always evaluates as true; it causes the current pathname (space separated) to be written to standard output.

This primary is not mentioned in the POSIX standard.

-prune

The primary always evaluates as true; it causes sfind not to descend the current pathname if it is a directory. If the -depth primary is specified, the -prune primary has no effect.

-readable

This primary evaluates as true if the file is readable by the real user id of the sfind process. The test is done by calling access(2).

This primary is not mentioned in the POSIX standard.

-sparse

The primary evaluates as true if the file appears to be sparse, this is when st_size > (st_blocks * DEV_BSIZE + DEV_BSIZE).

This primary is not mentioned in the POSIX standard.

-size n[c]

The primary evaluates as true if the file size in bytes, divided by 512 and rounded up to the next integer, is n. If n is followed by the character 'c', the size counts in bytes. If n is a size expression in the form used by sdd(1) (e.g. -size 10m or -size 7x8k) the the size also counts in bytes.

-true

This primary always evaluates to true.

This primary is not mentioned in the POSIX standard.

-time #

An alias for -mtime, try to avoid. This exists only for backwards compatibility with old sfind versions.

This primary is not mentioned in the POSIX standard.

-type c

The primary evaluates as true if the type of the file is c, where c is 'b', 'c', 'd', 'l', 'p', 'f', or 's' for block special file, character special file, directory, symbolic link, FIFO, regular file, or socket, respectively. The sfind implementation in addition supports 'D', 'e' and 'P' for the file types door, eventcount and event port.

-user uname

-user uid

The primary evaluates as true if the file belongs to the user uname. If uname is a decimal integer and the getpwnam() (or equivalent) function does not return a valid user name, uname is interpreted as a user ID.

-writable

This primary evaluates as true if the file is writable by the real user id of the sfind process. The test is done by calling access(2).

This primary is not mentioned in the POSIX standard.

-xattr

The primary evaluates as true if the file extended attributes. On platforms that do not support extended attributes or where sfind does not yet support extended attributes, the primary always evaluates as false. Currently only Solaris is supported.

This primary is not mentioned in the POSIX standard.

-xdev

The primary always evaluates as true; with older releases of libfind it was an alias to -mount for compatibility to AT&T UNIX implementations but it has become an alias to -mount+ after a POSIX standard bug fix in September 2018.

Note that the POSIX standard was aligned with the BSD/SunOS behavior from 1985 and differs from the AT&T UNIX behavior from 1988 for -xdev that was aligned with the behavior of nftw(3) with FTW_MOUNT that does not incude mount points in the output.

Since the original implementation for -xdev from BSD/SunOS from 1985 and the POSIX standard from 1992 require to report the directory type mount points, this has been finally set up for -xdev and libfind now follows the POSIX/BSD/SunOS wording.

The primaries can be combined using the following operators (in order of decreasing precedence):

( expression )

True if expression is true.

! expression

Negation of a primary; the unary NOT operator.

expression [-a] expression

Conjunction of primaries; the AND operator is implied by the juxtaposition of two primaries or made explicit by the optional -a operator. The second expression is not evaluated if the first expression is false.

expression -o expression

Alternation of primaries; the OR operator. The second expression is not evaluated if the first expression is true.

If no expression is present at all, -print is used as the default expression. Otherwise, if the given expression does not contain any of the primaries -exec, -ok, or -print, the given expression is effectively replaced by:

( given_expression ) -print

The -user, -group, and -newer primaries each evaluate their respective arguments only once.

EXAMPLES

sfind
sfind .
sfind . -print

They all write out the entire directory hierarchy from the current directory.

2. The following command:

sfind / \( -name tmp -o -name '*.xx' \) \
-atime +7 -exec rm {} \;

removes all files named tmp or ending in .xx that have not been accessed for seven or more 24-hour periods.

3. The following command:

sfind . -perm -o+w,+s

prints (-print is assumed) the names of all files in or below the current directory, with all of the file permission bits S_ISUID, S_ISGID, and S_IWOTH set.

4. The following command:

sfind . -name SCCS -prune -o -print

recursively prints pathnames of all files in the current directory and below, but skips directories named SCCS and files in them.

5. The following command:

sfind . -print -name SCCS -prune

behaves as in the previous example, but prints the names of the SCCS directories.

6. The following command is roughly equivalent to the -nt extension to test(1):

if [ -n `sfind file1 -prune -newer file2` ]; then
printf %s\\n "file1 is newer than file2"
fi

7. The descriptions of -atime, -ctime, and -mtime use the terminology n "86400 second periods (days)". For example, a file accessed at 23:59 is selected by:

sfind . -atime -1 -print

at 00:01 the next day (less than 24 hours later, not more than one day ago); the midnight boundary between days has no effect on the 24-hour calculation.

EXAMPLES USING POSIX EXTENSIONS

sfind / -mtime -1h15m -ls

lists all files that have been modified within less than 75 minutes from the start time of the sfind program.

RATIONALE

The descriptions of the '-' modifier on the mode and onum arguments to the -perm primary agree with historical practice on BSD and System V implementations. System V and BSD documentation both describe it in terms of checking additional bits; in fact, it uses the same bits, but checks for having at least all of the matching bits set instead of having exactly the matching bits set.

The exact format of the interactive prompts is unspecified. Only the general nature of the contents of prompts are specified because:

•

Implementations may desire more descriptive prompts than those used on historical implementations.

•

Since the historical prompt strings do not terminate with <newline>s, there is no portable way for another program to interact with the prompts of this utility via pipes.

Therefore, an application using this prompting option relies on the system to provide the most suitable dialog directly with the user, based on the general guidelines specified.

The -name file operand was changed to use the shell pattern matching notation so that find is consistent with other utilities using pattern matching.

The -size operand refers to the size of a file, rather than the number of blocks it may occupy in the file system. The intent is that the st_size field defined in the System Interfaces volume of IEEE Std 1003.1-2001 should be used, not the st_blocks found in historical implementations. There are at least two reasons for this:

1.

In both System V and BSD, find only uses st_size in size calculations for the operands specified by this volume of IEEE Std 1003.1-2001. (BSD uses st_blocks only when processing the -ls primary.)

2.

Users usually think of file size in terms of bytes, which is also the unit used by the ls utility for the output from the -l option. (In both System V and BSD, ls uses st_size for the -l option size field and uses st_blocks for the ls -s calculations. This volume of IEEE Std 1003.1-2001 does not specify ls -s.)

The descriptions of -atime, -ctime, and -mtime were changed from the SVID description of n "days'' to n being the result of the integer division of the time difference in seconds by 86400. The description is also different in terms of the exact timeframe for the n case (versus the +n or -n), but it matches all known historical implementations. It refers to one 86400 second period in the past, not any time from the beginning of that period to the current time. For example, -atime 2 is true if the file was accessed any time in the period from 72 hours to 48 hours ago.

Historical implementations do not modify "{}" when it appears as a substring of an -exec or -ok utility_name or argument string. There have been numerous user requests for this extension, so this volume of IEEE Std 1003.1-2001 allows the desired behavior. At least one recent implementation does support this feature, but encountered several problems in managing memory allocation and dealing with multiple occurrences of "{}" in a string while it was being developed, so it is not yet required behavior.

The sfind implementation does not modify "{}" when it appears as a substring as there is no problem to handle related issues by writing shell scripts or macros.

Assuming the presence of -print was added to correct a historical pitfall that plagues novice users, it is entirely upwards-compatible from the historical System V find utility. In its simplest form (find directory), it could be confused with the historical BSD fast find. The BSD developers agreed that adding -print as a default expression was the correct decision and have added the fast find functionality within a new utility called locate.

The sfind implementation in addition allows to be run without parameters. This results in the same output as if sfind . -print has been called. Do not use this extension in shell scripts for portability reasons.

Historically, the -L option was implemented using the primary -follow. The -H and -L options were added for two reasons. First, they offer a finer granularity of control and consistency with other programs that walk file hierarchies. Second, the -follow primary always evaluated to true. As they were historically really global variables that took effect before the traversal began, some valid expressions had unexpected results. An example is the expression -print -o -follow. Because -print always evaluates to true, the standard order of evaluation implies that -follow would never be evaluated. This was never the case. Historical practice for the -follow primary, however, is not consistent. Some implementations always follow symbolic links on the command line whether -follow is specified or not. Others follow symbolic links on the command line only if -follow is specified. Both behaviors are provided by the -H and -L options, but scripts using the current -follow primary would be broken if the -follow option is specified to work either way.

The sfind implementation always evaluates -follow. The difference between -follow and -L is that sfind writes a diagnostic message when a symbolic link does not point to a valid file if called with -follow while the symbolic link itself will be used with -L.

Since the -L option resolves all symbolic links and the -type l primary is true for symbolic links that still exist after symbolic links have been resolved, the command:

sfind -L . -type l

prints a list of symbolic links reachable from the current directory that do not resolve to accessible files.

A feature of SVR4's find utility was the -exec primary's + terminator. This allowed filenames containing special characters (especially <newline>s) to be grouped together without the problems that occur if such filenames are piped to xargs. Other implementations have added other ways to get around this problem, notably a -print0 primary that wrote filenames with a null byte terminator. This was considered here, but not adopted. Using a null terminator meant that any utility that was going to process find's -print0 output had to add a new option to parse the null terminators it would now be reading.

The "-exec ... {} +" syntax adopted was a result of IEEE PASC Interpretation 1003.2 #210. It should be noted that this is an incompatible change to the ISO/IEC 9899:1999 standard. For example, the following command prints all files with a '-' after their name if they are regular files, and a '+' otherwise:

sfind / -type f -exec echo {} - ';' -o -exec echo {} + ';'

The change invalidates usage like this. Even though the previous standard stated that this usage would work, in practice many did not support it and the standard developers felt it better to now state that this was not allowable.

ENVIRONMENT

LANG

Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.)

LC_ALL

If set to a non-empty string value, override the values of all the other internationalization variables.

LC_COLLATE

Determine the locale for the behavior of ranges, equivalence classes, and multi-character collating elements used in the pattern matching notation for the -n option and in the extended regular expression defined for the yesexpr locale keyword in the LC_MESSAGES category.

LC_CTYPE

This variable determines the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments), the behavior of character classes within the pattern matching notation used for the -n option, and the behavior of character classes within regular expressions used in the extended regular expression defined for the yesexpr locale keyword in the LC_MESSAGES category.

LC_MESSAGES

Determine the locale for the processing of affirmative responses that should be used to affect the format and contents of diagnostic messages written to standard error.

NLSPATH

[XSI] Determine the location of message catalogs for the processing of LC_MESSAGES.

PATH

Determine the location of the utility_name for the -exec and -ok primaries, as described in the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 8, Environment Variables.

EXIT STATUS

0

All path operands were traversed successfully.

>0

An error occurred.

STDIN

INPUT FILES

STDOUT

"%s\n", <path>

STDERR

Otherwise, the standard error is used only for diagnostic messages.

OUTPUT FILES

SEE ALSO

DIAGNOSTICS

NOTES

The bit that is traditionally used for sticky (historically 01000) is specified in the -perm primary using the octal number argument form. Since this bit is not defined by IEEE Std 1003.1-2001, applications must not assume that it actually refers to the traditional sticky bit.

At least one find implementation tries to speed up operation by avoiding to call stat(2) from making the assumption that a directory with a link count of st_nlink has st_nlink - 2 subdirectories. The IEEE Std 1003.1-2001 defines st_nlink to be undefined with directories. The rule above definitely does not apply for many file systems and even with traditional UNIX file systems, the assumption is not always true if there are hard links to directories. For this reason, the command:

find . -print

is fast but gives completely unpredictable results if a find implementation depends on this assumption. The sfind implementation has been made by preferring correct behavior before introducing dubious speed optimizations.

The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase ``this text'' refers to portions of the system documentation.

Portions of this text are reprinted and reproduced in electronic form in the sfind manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.

BUGS

AUTHOR

Joerg Schilling
D-13353 Berlin
Germany

Mail bugs and suggestions to:

joerg@schily.net