Improve wcurl version comparison mechanism

tests/curl-mock-version

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+# wcurl - a simple wrapper around curl to easily download files.
+#
+# This is wcurl's mock curl binary.
+#
+# Copyright (C) Samuel Henrique <samueloph@debian.org>, Sergio Durigan
+# Junior <sergiodj@debian.org> and many contributors, see the AUTHORS
+# file.
+#
+# Permission to use, copy, modify, and distribute this software for any purpose
+# with or without fee is hereby granted, provided that the above copyright
+# notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN
+# NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
+# OR OTHER DEALINGS IN THE SOFTWARE.
+#
+# Except as contained in this notice, the name of a copyright holder shall not be
+# used in advertising or otherwise to promote the sale, use or other dealings in
+# this Software without prior written authorization of the copyright holder.
+#
+# SPDX-License-Identifier: curl
+
+# This is a simple binary to mock curl's version string.  It will
+# print a version specified in the CURL_MOCK_VERSION variable and just
+# exit.  If CURL_MOCK_VERSION is empty, print 0.0.0.
+
+printf "%s\n" "curl ${CURL_MOCK_VERSION:-0.0.0}"
+exit 0

tests/tests.sh

@@ -233,6 +233,48 @@ testUrlDecodingNonLatinLanguages()
     assertContains "Verify whether 'wcurl' successfully decodes percent-encoded Korean in URLs" "${ret}" '퍼센트_인코딩'
 }
 
+testCurlBinaryOption()
+{
+    url='example.com'
+    ret=$(${WCURL_CMD} --dry-run "${url}")
+    bin=$(printf "%s" "${ret}" | head -n1)
+    assertEquals "Verify whether 'wcurl' invokes 'curl' when '--curl-binary' is not provided" "${bin}" "curl"
+
+    curlbin="${ROOTDIR}/tests/curl-mock-version"
+    ret=$(${WCURL_CMD} --dry-run --curl-binary "${curlbin}" "${url}")
+    bin=$(printf "%s" "${ret}" | head -n1)
+    assertContains "Verify whether 'wcurl' invokes the binary specified by '--curl-binary'" "${bin}" "${curlbin}"
+}
+
+testCurlVersionComparison()
+{
+    # Verify that using a very old curl version correctly omits
+    # --parallel, --no-clobber and --parallel-max-host.
+    url='example.com'
+    curlbin="${ROOTDIR}/tests/curl-mock-version"
+    ret=$(CURL_MOCK_VERSION="1.0.0" ${WCURL_CMD} --dry-run --curl-binary "${curlbin}" "${url}" "${url}")
+    assertNotContains "Verify whether 'wcurl' correctly omits --parallel when using very old curl" "${ret}" '--parallel'
+    assertNotContains "Verify whether 'wcurl' correctly omits --no-clobber when using very old curl" "${ret}" '--no-clobber'
+    assertNotContains "Verify whether 'wcurl' correctly omits --parallel-max-host when using very old curl" "${ret}" '--parallel-max-host'
+
+    # Verify that using a curl version that's >= 7.66.0 and < 7.83.0
+    # correctly adds --parallel but omits --no-clobber and --parallel-max-host.
+    ret=$(CURL_MOCK_VERSION="7.66.0" ${WCURL_CMD} --dry-run --curl-binary "${curlbin}" "${url}" "${url}")
+    assertContains "Verify whether 'wcurl' correctly adds --parallel when using curl >= 7.66.0" "${ret}" '--parallel'
+    assertNotContains "Verify whether 'wcurl' correctly omits --no-clobber when using curl >= 7.66.0 && curl < 7.83.0" "${ret}" '--no-clobber'
+    assertNotContains "Verify whether 'wcurl' correctly omits --parallel-max-host when using curl >= 7.66.0 && curl < 8.16.0" "${ret}" '--parallel-max-host'
+
+    # Verify that using a curl version that's >= 7.83.0 and < 8.16.0 correctly adds --no-clobber but omits --parallel-max-host.
+    ret=$(CURL_MOCK_VERSION="7.83.0" ${WCURL_CMD} --dry-run --curl-binary "${curlbin}" "${url}" "${url}")
+    assertContains "Verify whether 'wcurl' correctly adds --no-clobber when using curl >= 7.83.0" "${ret}" '--no-clobber'
+    assertNotContains "Verify whether 'wcurl' correctly omits --parallel-max-host when using curl >= 7.83.0 && curl < 8.16.0" "${ret}" '--parallel-max-host'
+
+    # Verify that using a curl version that's >= 8.16.0 correctly adds
+    # --parallel-max-host.
+    ret=$(CURL_MOCK_VERSION="8.16.0" ${WCURL_CMD} --dry-run --curl-binary "${curlbin}" "${url}" "${url}")
+    assertContains "Verify whether 'wcurl' correctly adds --parallel-max-host. when using curl >= 8.16.0" "${ret}" '--parallel-max-host'
+}
+
 ## Ideas for tests:
 ##
 ## - URL with whitespace

wcurl

@@ -49,8 +49,8 @@ usage()
 ${PROGRAM_NAME} -- a simple wrapper around curl to easily download files.
 
 Usage: ${PROGRAM_NAME} <URL>...
-       ${PROGRAM_NAME} [--curl-options <CURL_OPTIONS>]... [--no-decode-filename] [-o|-O|--output <PATH>] [--dry-run] [--] <URL>...
-       ${PROGRAM_NAME} [--curl-options=<CURL_OPTIONS>]... [--no-decode-filename] [--output=<PATH>] [--dry-run] [--] <URL>...
+       ${PROGRAM_NAME} [--curl-options <CURL_OPTIONS>]... [--curl-binary <CURL_BINARY>] [--no-decode-filename] [-o|-O|--output <PATH>] [--dry-run] [--] <URL>...
+       ${PROGRAM_NAME} [--curl-options=<CURL_OPTIONS>]... [--curl-binary=<CURL_BINARY>] [--no-decode-filename] [--output=<PATH>] [--dry-run] [--] <URL>...
        ${PROGRAM_NAME} -h|--help
        ${PROGRAM_NAME} -V|--version
 
@@ -59,6 +59,8 @@ Options:
   --curl-options <CURL_OPTIONS>: Specify extra options to be passed when invoking curl. May be
                                  specified more than once.
 
+  --curl-binary <CURL_BINARY>: Specify the curl binary to be used. By default, "curl" is used.
+
   -o, -O, --output <PATH>: Use the provided output path instead of getting it from the URL. If
                            multiple URLs are provided, resulting files share the same name with a
                            number appended to the end (curl >= 7.83.0). If this option is provided
@@ -89,6 +91,9 @@ error()
     exit 1
 }
 
+# The curl binary to be used.
+CURL_BINARY="curl"
+
 # Extra curl options provided by the user.
 # This is set per-URL for every URL provided.
 # Some options are global, but we are erroring on the side of needlessly setting
@@ -123,14 +128,49 @@ readonly UNSAFE_PERCENT_ENCODE="%2F %5C"
 # Whether to invoke curl or not.
 DRY_RUN="false"
 
+# The current version of curl.
+CURL_VERSION=""
+# The normalized curl version, in the format "XXYYZZ", where "XX" is
+# the zero-padded major version, "YY" is the zero-padded minor
+# version and "ZZ" is the zero-padded patch version.
+CURL_NORMALIZED_VERSION=""
+
 # Sanitize parameters.
 sanitize()
 {
     if [ -z "${URLS}" ]; then
         error "You must provide at least one URL to download."
     fi
 
-    readonly CURL_OPTIONS URLS DRY_RUN HAS_USER_SET_OUTPUT
+    CURL_VERSION=$(${CURL_BINARY} --version | head -n1 | cut -f2 -d' ')
+    if [ -z "${CURL_VERSION}" ]; then
+        error "Unable to determine curl version. Is curl installed?"
+    fi
+
+    CURL_NORMALIZED_VERSION=$(normalize_version "${CURL_VERSION}")
+
+    readonly CURL_OPTIONS \
+        CURL_BINARY \
+        URLS \
+        DRY_RUN \
+        HAS_USER_SET_OUTPUT \
+        CURL_VERSION \
+        CURL_NORMALIZED_VERSION
+}
+
+# Print the normalized format of a version specified as the first argument.
+#
+# The normalized version has the format "XXYYZZ", where "XX" is the
+# zero-padded major version, "YY" is the zero-padded minor version and
+# "ZZ" is the zero-padded patch version.
+normalize_version()
+{
+    version="${1}"
+    vermaj=$(printf "%s" "${version}" | cut -f1 -d.)
+    vermin=$(printf "%s" "${version}" | cut -f2 -d.)
+    verpatch=$(printf "%s" "${version}" | cut -f3 -d.)
+
+    printf "%02d%02d%02d" "${vermaj}" "${vermin}" "${verpatch}"
 }
 
 # Indicate via exit code whether the string given in the first parameter
@@ -198,36 +238,38 @@ get_url_filename()
     # No slash means there was just a hostname and no path; return empty string.
 }
 
+# Given a version (in the format MAJOR.MINOR) as the first argument
+# and an operator as the second argument, perform a comparison against
+# the current curl version.
+compare_curl_version()
+{
+    # Any of: -lt, -le, -eq, -gt, -ge
+    operator="${1}"
+    version="${2}"
+    version_to_compare=$(normalize_version "${version}")
+
+    test "${CURL_NORMALIZED_VERSION}" "${operator}" "${version_to_compare}"
+}
+
 # Execute curl with the list of URLs provided by the user.
 exec_curl()
 {
-    CMD="curl "
-
-    # Store version to check if it supports --no-clobber, --parallel and --parallel-max-host.
-    curl_version=$($CMD --version | cut -f2 -d' ' | head -n1)
-    curl_version_major=$(echo "$curl_version" | cut -f1 -d.)
-    curl_version_minor=$(echo "$curl_version" | cut -f2 -d.)
+    CMD="${CURL_BINARY} "
 
     CURL_NO_CLOBBER=""
     CURL_PARALLEL=""
 
-    if [ "${curl_version_major}" -ge 8 ]; then
+    # --parallel is only supported since 7.66.0.
+    if compare_curl_version -ge "7.66.0"; then
+        CURL_PARALLEL="--parallel"
+    fi
+    # --no-clobber is only supported since 7.83.0.
+    if compare_curl_version -ge "7.83.0"; then
         CURL_NO_CLOBBER="--no-clobber"
-        CURL_PARALLEL="--parallel --parallel-max-host 5"
-
-        # --parallel-max-host is only supported since 8.16.0.
-        if [ "${curl_version_major}" -eq 8 ] && [ "${curl_version_minor}" -lt 16 ]; then
-            CURL_PARALLEL="--parallel"
-        fi
-    elif [ "${curl_version_major}" -eq 7 ]; then
-        # --no-clobber is only supported since 7.83.0.
-        if [ "${curl_version_minor}" -ge 83 ]; then
-            CURL_NO_CLOBBER="--no-clobber"
-        fi
-        # --parallel is only supported since 7.66.0.
-        if [ "${curl_version_minor}" -ge 66 ]; then
-            CURL_PARALLEL="--parallel"
-        fi
+    fi
+    # --parallel-max-host is only supported since 8.16.0.
+    if compare_curl_version -ge "8.16.0"; then
+        CURL_PARALLEL="${CURL_PARALLEL} --parallel-max-host 5"
     fi
 
     # Detecting whether we need --parallel. It is easier to rely on
@@ -285,6 +327,16 @@ while [ -n "${1-}" ]; do
             CURL_OPTIONS="${CURL_OPTIONS} ${1}"
             ;;
 
+        --curl-binary=*)
+            opt=$(printf "%s\n" "${1}" | sed 's/^--curl-binary=//')
+            CURL_BINARY="${opt}"
+            ;;
+
+        --curl-binary)
+            shift
+            CURL_BINARY="${1}"
+            ;;
+
         --dry-run)
             DRY_RUN="true"
             ;;

wcurl.1

@@ -5,9 +5,9 @@
 .SH SYNOPSIS
 \fBwcurl <URL>...\fP
 
-\fBwcurl [\--curl\-options <CURL_OPTIONS>]... [\--dry\-run] [\--no\-decode\-filename] [\-o|\-O|\--output <PATH>] [\--] <URL>...\fP
+\fBwcurl [\--curl\-options <CURL_OPTIONS>]... [\--curl\-binary <CURL_BINARY>] [\--dry\-run] [\--no\-decode\-filename] [\-o|\-O|\--output <PATH>] [\--] <URL>...\fP
 
-\fBwcurl [\--curl\-options=<CURL_OPTIONS>]... [\--dry\-run] [\--no\-decode\-filename] [\--output=<PATH>] [\--] <URL>...\fP
+\fBwcurl [\--curl\-options=<CURL_OPTIONS>]... [\--curl\-binary=<CURL_BINARY>] [\--dry\-run] [\--no\-decode\-filename] [\--output=<PATH>] [\--] <URL>...\fP
 
 \fBwcurl \-V|\--version\fP
 
@@ -61,6 +61,8 @@ if there is none in the URL.
 .IP "--curl-options, --curl-options=\<CURL_OPTIONS\>..."
 Specify extra options to be passed when invoking curl. May be specified more
 than once.
+.IP "--curl-binary, --curl-binary=\<CURL_BINARY\>..."
+Specify the curl binary to be used. By default, "curl" is used.
 .IP "-o, -O, --output, --output=\<PATH\>"
 Use the provided output path instead of getting it from the URL. If multiple
 URLs are provided, resulting files share the same name with a number appended to

wcurl.md

@@ -18,9 +18,9 @@ Added-in: n/a
 
 **wcurl \<URL\>...**
 
-**wcurl [--curl-options \<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [-o|-O|--output \<PATH\>] [--] \<URL\>...**
+**wcurl [--curl-options \<CURL_OPTIONS\>]... [--curl-binary \<CURL_BINARY\>] [--dry-run] [--no-decode-filename] [-o|-O|--output \<PATH\>] [--] \<URL\>...**
 
-**wcurl [--curl-options=\<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [--output=\<PATH\>] [--] \<URL\>...**
+**wcurl [--curl-options=\<CURL_OPTIONS\>]... [--curl-binary=\<CURL_BINARY\>] [--dry-run] [--no-decode-filename] [--output=\<PATH\>] [--] \<URL\>...**
 
 **wcurl -V|--version**
 
@@ -78,6 +78,10 @@ By default, **wcurl** does:
 Specify extra options to be passed when invoking curl. May be specified more
 than once.
 
+## --curl-binary, --curl-binary=\<CURL_BINARY\>
+
+Specify the curl binary to be used. By default, "curl" is used.
+
 ## -o, -O, --output, --output=\<PATH\>
 
 Use the provided output path instead of getting it from the URL. If multiple