Qore Util Module Reference  1.3
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Util Namespace Reference

the Util namespace contains all the objects in the Util module More...

Classes

struct  UriQueryInfo
 the return value of the parse_uri_query() function More...
 

Functions

bool absolute_path (string path)
 returns True if the argument is an absolute path, False if not More...
 
bool absolute_path_unix (string path)
 returns True if the argument is a UNIX absolute path, False if not More...
 
bool absolute_path_windows (string path)
 returns True if the argument is a Windows absolute path, False if not More...
 
int compare_version (string lv, string rv)
 compares complex versions by breaking down strings into component parts More...
 
list flatten (softlist arg)
 Flattens a nested list (the nesting can be to any depth). More...
 
string get_byte_size (softnumber n, int decimals=2)
 returns a string giving a user-friendly real storage size (ie based on 1KiB = 1024 bytes) in KiB, MiB, GiB, TiB, etc for the given byte size More...
 
string get_exception_string (hash ex)
 returns a multi-line string from the exception hash argument suitable for logging or output on the console More...
 
string get_marketing_byte_size (softnumber n, int decimals=2)
 returns a string giving a user-friendly "marketing storage" size (ie based on 1KB = 1000 bytes) in KB, MB, GB, TB, etc for the given byte size More...
 
string get_random_string (softint len=15, int level=3)
 function that returns a random string More...
 
string glob_to_regex (string pat)
 Translates a shell pattern to a regular expression. More...
 
bool is_float (string text, bool pure=False)
 Checks whether string represents a (true) float value. More...
 
bool is_int (string text, bool pure=False)
 Checks whether string represents a (true) integer value. More...
 
bool is_number (string text, bool pure=False)
 Checks whether string represents a (true) number value. More...
 
string lpad (softstring text, int length, string padding= ' ')
 Returns a string left-padded to a specified length with the specified characters. More...
 
string make_uri_query (hash< UriQueryInfo > h, string arg_separator=";")
 returns a serialized string for a UriQueryInfo hash More...
 
string normalize_dir (string dir, string cwd=getcwd())
 returns a platform-specific normalized path name (starting from /, eliminates ".", "..", and "//") More...
 
string normalize_dir_unix (string dir, string cwd=getcwd())
 returns a normalized UNIX path name (starting from /, eliminates ".", "..", and "//") More...
 
string normalize_dir_windows (string dir, string cwd=getcwd())
 returns a normalized Windows path name (eliminates ".", "..", and "//") More...
 
string ordinal (int i)
 Returns string with partially textual representation of ordinal integer value. More...
 
auto parse_to_qore_value (string arg)
 tries to convert a string (such as an argument given from the command-line) to a Qore value More...
 
hash< UriQueryInfoparse_uri_query (string path)
 parses a URI path for a arguments and a method; where the method is the part of the path before the first "?" character, and arguments are after More...
 
string plural (int count, string base, string singular="", string plural="s")
 Returns string with number and proper singular/plural form of noun. More...
 
string regex_escape (string text)
 Escapes (backslashes) all non-alphanumeric characters in a string. More...
 
string rpad (softstring text, int length, string padding= ' ')
 Returns a string right-padded to a specified length with the specified characters. More...
 
bool same (list l)
 checks whether given list has only uniq element More...
 
list slice (list l, softlist indices)
 list slice implementation More...
 
string tmp_location ()
 Returns a path for temporary files. More...
 
list uniq (softlist arg)
 Returns a duplicate-free version of the list. More...
 
list zip ()
 Returns a list of lists, where the i-th list contains the i-th element from each of the argument lists. More...
 

Variables

const StorageNames = ("Kilo", "Mega", "Giga", "Tera", "Peta", "Exa", "Zetta", "Yotta", "Bronto")
 storage names (Geop, which would normally follow Bronto, is excluded as the abbreviation would be GB/GiB)
 

Detailed Description

the Util namespace contains all the objects in the Util module

Function Documentation

int Util::compare_version ( string  lv,
string  rv 
)

compares complex versions by breaking down strings into component parts

Example:
1 int result = compare_version("2.11.1", "2.2");

Each element is compared separately, so that compare_version("2.11.1", "2.2") returns 1 (a regular string comparison would give the opposite result)

Parameters
lvleft-hand version
rvright-hand version
Returns
-1 if lv < rv, 0 if equal, and 1 if lv > rv
list Util::flatten ( softlist  arg)

Flattens a nested list (the nesting can be to any depth).

Parameters
arga list to flatten
Returns
a flattened list
Example:
1 list f = flatten (((1, 2), (3, 4), 5)); # returns (1, 2, 3, 4, 5)
Since
Util 1.3
string Util::get_byte_size ( softnumber  n,
int  decimals = 2 
)

returns a string giving a user-friendly real storage size (ie based on 1KiB = 1024 bytes) in KiB, MiB, GiB, TiB, etc for the given byte size

Example:
1 string str = get_byte_size(n);
Parameters
nthe number to display
decimalsthe number of digits after the decimal point
string Util::get_exception_string ( hash  ex)

returns a multi-line string from the exception hash argument suitable for logging or output on the console

Parameters
exthe exception hash to process
Returns
a multi-line string from the exception hash argument suitable for logging or output on the console
string Util::get_marketing_byte_size ( softnumber  n,
int  decimals = 2 
)

returns a string giving a user-friendly "marketing storage" size (ie based on 1KB = 1000 bytes) in KB, MB, GB, TB, etc for the given byte size

Example:
1 string str = get_marketing_byte_size(n);
Parameters
nthe number to display
decimalsthe number of digits after the decimal point
string Util::get_random_string ( softint  len = 15,
int  level = 3 
)

function that returns a random string

Example:
1 string pass = get_random_string();
Parameters
lenthe length fo the string returned
levela value from 1 - 4 inclusive giving the range of printable ASCII characters included in the output (values out of the range result in the nearest value in the range being used):
  • 1: only upper case
  • 2: +lower case
  • 3: +numbers
  • 4: +symbols but not including any quote characters
Returns
a random string of the given length containing only printable ASCII characters according to the level argument
See Also
Qore::get_random_bytes()
string Util::glob_to_regex ( string  pat)

Translates a shell pattern to a regular expression.

Returns the shell-style pattern converted to a regular expression.

Parameters
patthe pattern to convert
Returns
a converted pattern
Example:
1 string s = glob_to_regex ("*.*"); # returns ".*\\..*"
Since
Util 1.2
bool Util::is_float ( string  text,
bool  pure = False 
)

Checks whether string represents a (true) float value.

Parameters
texta string to check
pureif True then only floats match, otherwise include integers.
Returns
True if input represents a float value, False otherwise.
Example:
1 bool match = is_float("1.2");
2 # returns True, while any of the following returns False:
3 match = is_float("12", True);
4 match = is_float("1.2x");
Note
The function only checks whether a string represents a float value, but it does not validate size / precision restrictions (whether it would fit Qore's native float type).
Since
Util 1.2
bool Util::is_int ( string  text,
bool  pure = False 
)

Checks whether string represents a (true) integer value.

Parameters
texta string to check
pureif True then only integers match, otherwise check floats too.
Returns
True if input represents an integer value, False otherwise.
Example:
1 bool match = is_int("123");
2 # returns True, while any of the following returns False:
3 match = is_int("1.0", True);
4 match = is_int("12x");
Note
The function only checks whether a string represents an integer value, but it does not validate size restrictions (that is whether it would fit Qore's native int type) etc.
Since
Util 1.2
bool Util::is_number ( string  text,
bool  pure = False 
)

Checks whether string represents a (true) number value.

Parameters
texta string to check
pureif True then only numbers match, otherwise include floats and integers.
Returns
True if input represents a number value, False otherwise.
Example:
1 bool match = is_number("1.2n");
2 # returns True, while any of the following returns False:
3 match = is_number("12", True);
4 match = is_number("1.2", True);
5 match = is_number("1.2x");
Note
The function only checks whether a string represents an arbitrary precision number value, but it does not validate any restrictions (whether it would fit Qore's native number type).
Since
Util 1.2
string Util::lpad ( softstring  text,
int  length,
string  padding = ' ' 
)

Returns a string left-padded to a specified length with the specified characters.

Returns a string, left-padded to a specified length with the specified characters; or, when the string to be padded is longer than the length specified after padding, only that portion of the string that fits into the specified length.

Parameters
textinput string that you want to pad
lengthtotal length of output string (in characters)
paddingpadding character(s); default value is a single blank
Returns
a string left-padded to the specified length
Example:
1 string s = lpad ("123", 5); # returns " 123"
2 string s = lpad ("ABC", 9, "-"); # returns "------ABC"
Since
Util 1.2
string Util::make_uri_query ( hash< UriQueryInfo >  h,
string  arg_separator = ";" 
)

returns a serialized string for a UriQueryInfo hash

Parameters
hthe UriQueryInfo hash to serialize
arg_separatorthe character to use to separate URI query arguments
Since
Util 1.3
string Util::normalize_dir ( string  dir,
string  cwd = getcwd() 
)

returns a platform-specific normalized path name (starting from /, eliminates ".", "..", and "//")

Example:
1 string dir = normalize_dir(dir);

Currently only Windows and UNIX-style directories are supported; this function calls either:

Parameters
dirthe directory name to normalize
cwdthe current working directory for normalizing relative paths
Returns
a normalized path name for the current platform
See Also
string Util::normalize_dir_unix ( string  dir,
string  cwd = getcwd() 
)

returns a normalized UNIX path name (starting from /, eliminates ".", "..", and "//")

Example:
1 string dir = normalize_dir_unix(dir, "/var/tmp");

For example, calling:

1 normalize_dir("../../test/.//dir");

from current directory "/opt/qorus/sub/dir" returns:

1 "/opt/qorus/test/dir"
Parameters
dirthe directory name to normalize
cwdthe current working directory
Returns
a normalized path name (starting from /, eliminates ".", "..", and "//")
string Util::normalize_dir_windows ( string  dir,
string  cwd = getcwd() 
)

returns a normalized Windows path name (eliminates ".", "..", and "//")

Example:
1 string dir = normalize_dir_windows(dir, "c:\\qore"));

For example, calling:

1 normalize_dir("..\..\test\.\\dir");

from current directory "c:\\lang\\qore\\prog1" returns:

1 "c:\\lang\\test\\dir"
Parameters
dirthe directory name to normalize
cwdthe current working directory
Returns
a normalized path name; eliminates ".", "..", and "\\" (except at the beginning of a UNC path)
string Util::ordinal ( int  i)

Returns string with partially textual representation of ordinal integer value.

Example:
1 printf ("%s grade", ordinal(1));
2 # would print "1st grade"
Parameters
iinteger value to convert to textual representation
Returns
a string representation of ordinal value of the argument
Since
Util 1.2
auto Util::parse_to_qore_value ( string  arg)

tries to convert a string (such as an argument given from the command-line) to a Qore value

This function recognizes two special prefixes in the string:

  • STR= this prefix indicates that the rest of the string should be passed literally and not parsed
  • EVAL= this prefix indicates that the rest of the string should be taken as a Qore expression and executed and the value returned

Strings are interpreted as in the following table.

String Parsing

Format Description
key_string = value[, ...] a hash
value, [...] a list
integers an integer
floats a float
arbitrary-numeric value a number
True, true, False, false a bool
YYYY-MM-DD[[-T ]HH:mm[:SS[.uu]]] a date
a Qore expression the value evaluated
a quoted string a string
Examples:
prompt% qore -l Util -X 'parse_to_qore_value("(a=(b=(c=x, 2, 3)))")'
hash: (1 member)
  a : hash: (1 member)
    b : list: (3 elements)
      [0]=hash: (1 member)
        c : "x"
      [1]=2
      [2]=3
Parameters
arga string to convert to a Qore value according to the rules documented above
Returns
the Qore value corresponding to the input string
Exceptions
PARSE-ERRORcannot parse the string given
hash<UriQueryInfo> Util::parse_uri_query ( string  path)

parses a URI path for a arguments and a method; where the method is the part of the path before the first "?" character, and arguments are after

Parameters
paththe URI path to parse
Returns
a UriQueryInfo hash
Note
the params output key value is always returned as a hash
Since
Util 1.3
string Util::plural ( int  count,
string  base,
string  singular = "",
string  plural = "s" 
)

Returns string with number and proper singular/plural form of noun.

Parameters
countinteger value to convert
basebase word or possibly nothing
singularsingular form suffix or whole word
pluralplural form suffix or whole word
Returns
a string representation of number plus noun
Example:
1 printf (plural(1, "beer"));
2 # would print "1 beer"
3 printf (plural(1, "lad", "y", "ies"));
4 # would print "1 lady"
5 printf (plural(32, "", "tooth", "teeth"));
6 # would print "32 teeth"
Since
Util 1.2
string Util::regex_escape ( string  text)

Escapes (backslashes) all non-alphanumeric characters in a string.

Returns string with all non-alphanumerics backslashed; this is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it.

Parameters
textstring to escape / backslash
Returns
a string escaped / backslashed
Example:
1 string s = regex_escape ("Gain: $100"); # returns "Gain\\:\\ \\$100"
Since
Util 1.2
string Util::rpad ( softstring  text,
int  length,
string  padding = ' ' 
)

Returns a string right-padded to a specified length with the specified characters.

Returns a string, right-padded to a specified length with the specified characters; or, when the string to be padded is longer than the length specified after padding, only that portion of the string that fits into the specified length.

Parameters
textinput string that you want to pad
lengthtotal length of output string (in characters)
paddingpadding character(s); default value is a single blank
Returns
a string right-padded to the specified length
Example:
1 string s = rpad ("123", 5); # returns "123 "
2 string s = rpad ("ABC", 9, "-"); # returns "ABC------"
Since
Util 1.2
bool Util::same ( list  l)

checks whether given list has only uniq element

Example:
1 if (same((1, 1, 1)) {
2  printf("only uniq element");
3 };
Parameters
lsome list
Since
Util 1.2
list Util::slice ( list  l,
softlist  indices 
)

list slice implementation

Example:
1 list_slice(("a", "b", "c", "d"), (1, 3)); # returns ("b", "d")
Parameters
lsome list
indicesindices that should be sliced from the original list
Since
Util 1.2
string Util::tmp_location ( )

Returns a path for temporary files.

Example:
1 string testfile = tmp_location() + '/test.txt';
2 # some processing
3 unlink(testfile);

Environment variables are searched in the following order (the first with a value is used):

  • TMPDIR
  • TMP
  • TEMP
  • TEMPDIR

If none of these are present, then "/tmp" (UNIX) or "c:\temp" (Windows) is checked.

Exceptions
TMP-ERRORunable to find the location of the temporary directory; temporary directory is not writable
Since
Util 1.2
list Util::uniq ( softlist  arg)

Returns a duplicate-free version of the list.

Parameters
arga list of values to filter out
Returns
a list of unique values
Example:
1 list u = uniq ((1,2,1,3,2,1)); # returns (1,2,3)
Note
Since implementation of this function uses hash to keep track of the list values, it cannot safely process values which implicit string representation collide (e.g. float values that differ outside implicit toString() precision).
Exceptions
UNIQ-ERRORif two different values from the list share the same implicit string representation
Since
Util 1.3
list Util::zip ( )

Returns a list of lists, where the i-th list contains the i-th element from each of the argument lists.

Parameters
...lists to 'zip'
Returns
a list of lists
Example:
1 list z = zip ((1, 2, 3), (4, 5)); # returns ((1,4), (2,5), (3,NOTHING))
Since
Util 1.2