qmake provides functions for processing the contents of variables during the configuration process. These functions are called replace functions. Typically, they return values that you can assign to other variables.
You can obtain these values by prefixing a function with the $$
operator. Replace functions can be divided into built-in functions and function libraries.
See also Test Functions.
Basic replace functions are implemented as built-in functions.
Returns the absolute path of path
.
If base
is not specified, uses the current directory as the base directory. If it is a relative path, it is resolved relative to the current directory before use.
For example, the following call returns the string "/home/johndoe/myproject/readme.txt"
:
message($$absolute_path("readme.txt", "/home/johndoe/myproject"))
See also clean_path(), relative_path().
Returns the basename of the file specified in variablename
.
For example:
FILE = /etc/passwd FILENAME = $$basename(FILE) #passwd
Returns the contents of filename
. You can specify the following options for mode
:
blob
returns the entire contents of the file as one valuelines
returns each line as a separate value (without line endings)true
(default value) and false
return file contents as separate values, split according to qmake value list splitting rules (as in variable assignments). If mode
is
false
, values that contain only a newline character are inserted into the list to indicate where line breaks were in the file.Returns path
with directory separators normalized (converted to "/") and redundant ones removed, and "."s and ".."s resolved (as far as possible). This function is a wrapper around QDir::cleanPath.
See also absolute_path(), relative_path(), shell_path(), system_path().
Returns the directory name part of the specified file. For example:
FILE = /etc/X11R6/XF86Config DIRNAME = $$dirname(FILE) #/etc/X11R6
Returns a list of all defined variable names.
Accepts an arbitrary number of arguments. It expands the escape sequences \n
, \r
, \t
for each argument and returns the arguments as a list.
Note: If you specify the string to expand literally, you need to escape the backslashes, as illustrated by the following code snippet:
message("First line$$escape_expand(\\n)Second line")
Returns all the values in variablename
that match the regular expression substr
.
MY_VAR = one two three four MY_VAR2 = $$join(MY_VAR, " -L", -L) -Lfive MY_VAR3 = $$member(MY_VAR, 2) $$find(MY_VAR, t.*)
MY_VAR2 will contain '-Lone -Ltwo -Lthree -Lfour -Lfive', and MY_VAR3 will contain 'three two three'.
Expands the specified wildcard pattern and returns a list of filenames. If recursive
is true, this function descends into subdirectories.
Returns the first value of variablename
.
For example, the following call returns firstname
:
CONTACT = firstname middlename surname phone message($$first(CONTACT))
See also take_first(), last().
Returns number
in the format specified by options
. You can specify the following options:
ibase=n
sets the base of the input to n
obase=n
sets the base of the output to n
width=n
sets the minimum width of the output to n
. If the output is shorter than width
, it is padded with spaceszeropad
pads the output with zeroes instead of spacespadsign
prepends a space to positive values in the outputalwayssign
prepends a plus sign to positive values in the outputleftalign
places the padding to the right of the value in the outputFloating-point numbers are currently not supported.
For example, the following call converts the hexadecimal number BAD
to 002989
:
message($$format_number(BAD, ibase=16 width=6 zeropad))
Evaluates filename
as a qmake project file and returns the value assigned to variablename
.
See also infile().
Returns the value of the environment variable variablename
. This is mostly equivalent to the $$(variablename)
syntax. The getenv
function, however, supports environment variables with
parentheses in their name.
Joins the value of variablename
with glue
. If this value is not empty, this function prefixes the value with before
and suffixes it with after
. variablename
is
the only required field, the others default to empty strings. If you need to encode spaces in glue
, before
, or after
, you must quote them.
Returns the last value of variablename
.
For example, the following call returns phone
:
CONTACT = firstname middlename surname phone message($$last(CONTACT))
See also take_last(), first().
Takes an arbitrary number of arguments. It creates a uniquely named variable that contains a list of the arguments, and returns the name of that variable. You can use the variable to write a loop as illustrated by the following code snippet
for(var, $$list(foo bar baz)) { ... }
instead of:
values = foo bar baz for(var, values) { ... }
Takes an arbitrary number of arguments and converts them to lower case.
See also upper().
Returns the slice of the list value of variablename
with the zero-based element indices between start
and end
(inclusive).
If start
is not given, it defaults to zero. This usage is equivalent to $$first(variablename)
.
If end
is not given, it defaults to start
. This usage represents simple array indexing, as exactly one element will be returned.
It is also possible to specify start and end in a single argument, with the numbers separated by two periods.
Negative numbers represent indices starting from the end of the list, with -1 being the last element.
If either index is out of range, an empty list is returned.
If end
is smaller than start
, the elements are returned in reverse order.
Note: The fact that the end index is inclusive and unordered implies that an empty list will be returned only when an index is invalid (which is implied by the input variable being empty).
See also str_member().
Takes an arbitrary number of numeric arguments and adds them up, returning the sum.
Subtraction is implicitly supported due to the possibility to simply prepend a minus sign to a numeric value to negate it:
sum = $$num_add($$first, -$$second)
If the operand may be already negative, another step is necessary to normalize the number:
second_neg = -$$second second_neg ~= s/^--// sum = $$num_add($$first, $$second_neg)
Displays the specified question
, and returns a value read from stdin.
If decorate
is true (the default), the question gets a generic prefix and suffix identifying it as a prompt.
Converts a whole string
into a single entity and returns the result. This is just a fancy way of enclosing the string into double quotes.
Returns the string
with every special regular expression character escaped with a backslash. This function is a wrapper around QRegExp::escape.
Returns the path to filePath
relative to base
.
If base
is not specified, it is the current project directory. If it is relative, it is resolved relative to the current project directory before use.
If filePath
is relative, it is first resolved against the base directory; in that case, this function effectively acts as $$clean_path().
See also absolute_path(), clean_path().
Replaces each instance of old_string
with new_string
in the contents of the variable supplied as string
. For example, the code
MESSAGE = This is a tent. message($$replace(MESSAGE, tent, test))
prints the message:
This is a test.
This is an internal function that you will typically not need.
Returns the values of variablename
in reverse order.
Returns a section of the value of variablename
. This function is a wrapper around QString::section.
For example, the following call outputs surname
:
CONTACT = firstname:middlename:surname:phone message($$section(CONTACT, :, 2, 2))
Maps the path from the project source directory to the build directory. This function returns path
for in-source builds. It returns an empty string if path
points outside of the source
tree.
Converts all directory separators within path
to separators that are compatible with the shell that is used while building the project (that is, the shell that is invoked by the make tool). For example, slashes
are converted to backslashes when the Windows shell is used.
See also system_path().
Quotes arg
for the shell that is used while building the project.
See also system_quote().
Returns the number of values of variablename
.
See also str_size().
This is an internal function that you will typically not need.
Returns the list of values in variablename
with entries sorted in ascending ASCII order.
Numerical sorting can be accomplished by zero-padding the values to a fixed length with the help of the format_number() function.
Splits the value of variablename
into separate values, and returns them as a list. This function is a wrapper around QString::split.
For example:
CONTACT = firstname:middlename:surname:phone message($$split(CONTACT, :))
Replaces %1-%9 in string
with the arguments passed in the comma-separated list of function arguments
and returns the processed string.
This function is identical to member(), except that it operates on a string value instead of a list variable, and consequently the indices refer to character positions.
This function can be used to implement many common string slicing operations:
# $$left(VAR, len) left = $$str_member(VAR, 0, $$num_add($$len, -1)) # $$right(VAR, len) right = $$str_member(VAR, -$$num, -1) # $$mid(VAR, off, len) mid = $$str_member(VAR, $$off, $$num_add($$off, $$len, -1)) # $$mid(VAR, off) mid = $$str_member(VAR, $$off, -1) # $$reverse(VAR) reverse = $$str_member(VAR, -1, 0)
Note: In these implementations, a zero len
argument needs to be handled separately.
Returns the number of characters in the argument.
See also size().
You can use this variant of the system
function to obtain stdout from the command and assign it to a variable.
For example:
UNAME = $$system(uname -s) contains( UNAME, [lL]inux ):message( This looks like Linux ($$UNAME) to me )
If you pass stsvar
, the command's exit status will be stored in that variable. If the command crashes, the status will be -1, otherwise a non-negative exit code of the command's choosing. Usually, comparing the
status with zero (success) is sufficient.
See also the test variant of system().
Converts all directory separators within path
to separators that are compatible with the shell that is used by the system()
functions to invoke commands. For example, slashes are converted to
backslashes for the Windows shell.
See also shell_path().
Quotes arg
for the shell that is used by the system()
functions.
See also shell_quote().
Returns the first value of variablename
and removes it from the source variable.
This provides convenience for implementing queues, for example.
See also take_last(), first().
Returns the last value of variablename
and removes it from the source variable.
This provides convenience for implementing stacks, for example.
See also take_first(), last().
Returns the list of values in variablename
with duplicate entries removed. For example:
ARGS = 1 2 3 2 5 1 ARGS = $$unique(ARGS) #1 2 3 5
Takes an arbitrary number of arguments and converts them to upper case.
See also lower().
Escapes the values of variablename
in a way that enables parsing them as qmake code.