Introduce new options for downloading a list of URLs from file

 There are two ways of doing this now:
 1) wget way: -i, --input-file
 2) curl way: providing an URL argument starting with "@", wcurl will
    see "@filename" and download URLs from "filename".

 Lines starting with "#" inside input files are ignored.

 This is a continuation of #58

Author: samueloph

README.md

@@ -42,8 +42,9 @@ sudo mandb
 
 ```text
 wcurl <URL>...
-wcurl [--curl-options <CURL_OPTIONS>]... [--no-decode-filename] [-o|-O|--output <PATH>] [--dry-run] [--] <URL>...
-wcurl [--curl-options=<CURL_OPTIONS>]... [--no-decode-filename] [--output=<PATH>] [--dry-run] [--] <URL>...
+wcurl -i <INPUT_FILE>...
+wcurl [--curl-options <CURL_OPTIONS>]... [--no-decode-filename] [-o|-O|--output <PATH>] [-i|--input-file <PATH>]... [--dry-run] [--] <URL>...
+wcurl [--curl-options=<CURL_OPTIONS>]... [--no-decode-filename] [--output=<PATH>] [--input-file=<PATH>]... [--dry-run] [--] <URL>...
 wcurl -V|--version
 wcurl -h|--help
 ```
@@ -85,6 +86,12 @@ should be using curl directly if your use case is not covered.
   the end (curl >= 7.83.0). If this option is provided multiple times, only the
   last value is considered.
 
+* `-i, --input-file=<PATH>`
+
+  Download all URLs listed in the input file. Can be used multiple times and
+  mixed with URLs as parameters. This is equivalent to setting "@\<PATH\>" as an
+  URL argument. Lines starting with "#" are ignored.
+
 * `--no-decode-filename`
 
   Don't percent-decode the output filename, even if the percent-encoding in the
@@ -112,6 +119,8 @@ instead forwarded to the curl invocation.
 URL to be downloaded. Anything that is not a parameter is considered
 an URL. Whitespaces are percent-encoded and the URL is passed to curl, which
 then performs the parsing. May be specified more than once.
+Arguments starting with "@" are considered as a file listing multiple URLs to
+be downloaded; "@\<PATH\>" is equivalent to using "--input-file \<PATH\>".
 
 # Examples
 

wcurl

@@ -49,8 +49,9 @@ 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} -i <INPUT_FILE>...
+       ${PROGRAM_NAME} [--curl-options <CURL_OPTIONS>]... [--no-decode-filename] [-o|-O|--output <PATH>] [-i|--input-file <PATH>]... [--dry-run] [--] [<URL>]...
+       ${PROGRAM_NAME} [--curl-options=<CURL_OPTIONS>]... [--no-decode-filename] [--output=<PATH>] [--input-file=<PATH>]... [--dry-run] [--] [<URL>]...
        ${PROGRAM_NAME} -h|--help
        ${PROGRAM_NAME} -V|--version
 
@@ -64,6 +65,10 @@ Options:
                            number appended to the end (curl >= 7.83.0). If this option is provided
                            multiple times, only the last value is considered.
 
+  -i, --input-file <PATH>: Download all URLs listed in the input file. Can be used multiple times
+                           and mixed with URLs as parameters. This is equivalent to setting
+                           "@<PATH>" as an URL argument. Lines starting with "#" are ignored.
+
   --no-decode-filename: Don't percent-decode the output filename, even if the percent-encoding in
                         the URL was done by wcurl, e.g.: The URL contained whitespaces.
 
@@ -79,6 +84,8 @@ Options:
   <URL>: URL to be downloaded. Anything that is not a parameter is considered
          an URL. Whitespaces are percent-encoded and the URL is passed to curl, which
          then performs the parsing. May be specified more than once.
+         Arguments starting with "@" are considered as a file listing multiple URLs to be
+         downloaded; "@<PATH>" is equivalent to using "--input-file <PATH>".
 _EOF_
 }
 
@@ -116,6 +123,33 @@ readonly PER_URL_PARAMETERS="\
 # Whether to invoke curl or not.
 DRY_RUN="false"
 
+# Add URLs to list of URLs to be downloaded.
+# If the argument starts with "@", then it's an input file name.
+# When parsing an input file, ignore lines starting with "#".
+# This function also percent-encodes the whitespaces in URLs.
+add_urls()
+{
+    case "$1" in
+        @*)
+            while read -r url; do
+                case "$url" in
+                    \#*) ;;
+                    *)
+                        # Percent-encode whitespaces into %20, since wget supports those URLs.
+                        newurl=$(printf "%s\n" "${url}" | sed 's/ /%20/g')
+                        URLS="${URLS} ${newurl}"
+                        ;;
+                esac
+            done < "${1#@}"
+            ;;
+        *)
+            # Percent-encode whitespaces into %20, since wget supports those URLs.
+            newurl=$(printf "%s\n" "${1}" | sed 's/ /%20/g')
+            URLS="${URLS} ${newurl}"
+            ;;
+    esac
+}
+
 # Sanitize parameters.
 sanitize()
 {
@@ -280,6 +314,19 @@ while [ -n "${1-}" ]; do
             OUTPUT_PATH="${opt}"
             ;;
 
+        --input-file=*)
+            add_urls "@$(printf "%s\n" "${1}" | sed 's/^--input-file=//')"
+            ;;
+
+        -i | --input-file)
+            shift
+            add_urls "@${1}"
+            ;;
+
+        -i*)
+            add_urls "@$(printf "%s\n" "${1}" | sed 's/^-[i]//')"
+            ;;
+
         --no-decode-filename)
             DECODE_FILENAME="false"
             ;;
@@ -297,10 +344,8 @@ while [ -n "${1-}" ]; do
         --)
             # This is the start of the list of URLs.
             shift
-            for url in "$@"; do
-                # Encode whitespaces into %20, since wget supports those URLs.
-                newurl=$(printf "%s\n" "${url}" | sed 's/ /%20/g')
-                URLS="${URLS} ${newurl}"
+            for arg in "$@"; do
+                add_urls "${arg}"
             done
             break
             ;;
@@ -311,9 +356,7 @@ while [ -n "${1-}" ]; do
 
         *)
             # This must be a URL.
-            # Encode whitespaces into %20, since wget supports those URLs.
-            newurl=$(printf "%s\n" "${1}" | sed 's/ /%20/g')
-            URLS="${URLS} ${newurl}"
+            add_urls "${1}"
             ;;
     esac
     shift

wcurl.md

@@ -18,9 +18,11 @@ Added-in: n/a
 
 **wcurl \<URL\>...**
 
-**wcurl [--curl-options \<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [-o|-O|--output \<PATH\>] [--] \<URL\>...**
+**wcurl -i \<INPUT_FILE\>...**
 
-**wcurl [--curl-options=\<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [--output=\<PATH\>] [--] \<URL\>...**
+**wcurl [--curl-options \<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [-o|-O|--output \<PATH\>] [-i|--input-file \<PATH\>]... [--] [\<URL\>]...**
+
+**wcurl [--curl-options=\<CURL_OPTIONS\>]... [--dry-run] [--no-decode-filename] [--output=\<PATH\>] [--input-file=\<PATH\>]... [--] [\<URL\>]...**
 
 **wcurl -V|--version**
 
@@ -82,6 +84,12 @@ 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 multiple times, only the
 last value is considered.
 
+## -i, --input-file=\<PATH\>
+
+Download all URLs listed in the input file. Can be used multiple times and
+mixed with URLs as parameters. This is equivalent to setting "@\<PATH\>" as an
+URL argument. Lines starting with "#" are ignored.
+
 ## --no-decode-filename
 
 Don't percent-decode the output filename, even if the percent-encoding in the
@@ -109,6 +117,8 @@ is instead forwarded to the curl invocation.
 URL to be downloaded. Anything that is not a parameter is considered
 an URL. Whitespaces are percent-encoded and the URL is passed to curl, which
 then performs the parsing. May be specified more than once.
+Arguments starting with "@" are considered as a file listing multiple URLs to be
+downloaded; "@\<PATH\>" is equivalent to using "--input-file \<PATH\>".
 
 # EXAMPLES