PATTERN+PROCS is a list of regexp/two-argument-procedure pairs. For each line of FILE, and for each PATTERN that it matches, call the corresponding PROC as (PROC LINE MATCHES); PROC must return the line that will be written as a substitution of the original line. Be careful about using '$' to match the end of a line; by itself it won't match the terminating newline of a line.

Patch the `SHELL' variable in FILE, which is supposedly a makefile. When KEEP-MTIME? is true, the atime/mtime of FILE are kept unchanged.

Report to PORT about C, an '&invoke-error' condition, in a human-friendly way.

Return true if FILE starts with the right magic bytes.

Replace the first pair in ALIST whose car is KEY with the KEY/VALUE pair. An error is raised when no such pair exists.

Return a predicate that returns true when passed a file name whose base name matches REGEXP.

Return true if FILE starts with the right magic bytes.

Read LEN bytes from IN or as much data as possible if LEN is #f, and write it to OUT, using chunks of BUFFER-SIZE bytes. Call PROGRESS at the beginning and after each successful transfer of BUFFER-SIZE bytes or less, passing it the total number of bytes transferred and the continuation of the transfer as a thunk.

Invoke PROGRAM with the given ARGS. Raise an exception if the exit code is non-zero; otherwise return #t.

Return #t if FILE is a symbolic link (aka. "symlink".)

True when FILE-NAME has a tar file extension.

Insert the KEY/VALUE pair before the first occurrence of a pair whose key is REFERENCE in ALIST. Use KEY=? to compare keys. An error is raised when no such pair exists.

Look for each of FILES of the given TYPE (a symbol as returned by 'stat:type') in INPUT-DIRS. Set ENV-VAR to a SEPARATOR-separated path accordingly. Example:

(set-path-environment-variable "PKG_CONFIG" '("lib/pkgconfig") (list package1 package2))

When PATTERN is not #f, it must be a regular expression (really a string) denoting file names to look for under the directories designated by FILES:

(set-path-environment-variable "XML_CATALOG_FILES" '("xml") (list docbook-xml docbook-xsl) #:type 'regular #:pattern "^catalog\\.xml$")

Create a desktop entry file at DESTINATION. You must specify NAME.

Values can be booleans, numbers, strings or list of strings.

Additionally, locales can be specified with an alist where the key is the locale. The #f key specifies the default. Example:

#:name '((#f "I love Guix") ("fr" "J'aime Guix"))

produces

Name=I love Guix Name[fr]=J'aime Guix

For a complete description of the format, see the specifications at https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html.

Return true if FILE starts with the right magic bytes.

Invoke PROGRAM with ARGS and capture PROGRAM's standard output and standard error. If PROGRAM succeeds, print nothing and return the unspecified value; otherwise, raise a '&message' error condition that includes the status code and the output of PROGRAM.

Call PROC with two arguments: an input port for FILE, and an output port for the file that is going to replace FILE. Upon success, FILE is atomically replaced by what has been written to the output port, and PROC's result is returned.