Add a bunch of commandline options for controlling I/O format.

Also docs for the above. Closes #1.

docs/content/3.manual/manual.yml

@@ -28,7 +28,59 @@ body: |
   simpler:
   
 sections:
-  - title: Basics
+  - title: Invoking jq
+    body: |
+      
+      jq filters run on a stream of JSON data. The input to jq is
+      parsed as a sequence of whitespace-separated JSON values which
+      are passed through the provided filter one at a time. The
+      output(s) of the filter are written to standard out, again as a
+      sequence of whitespace-separated JSON data.
+
+      You can affect how jq reads and writes its input and output
+      using some command-line options:
+
+      * `--slurp`/`-s` 
+
+        Instead of running the filter for each JSON object in the
+        input, read the entire input stream into a large array and run
+        the filter just once.
+      
+      * `--raw-input`/`-R` 
+      
+        Don't parse the input as JSON. Instead, each line of text is
+        passed to the filter as a string. If combined with `--slurp`,
+        then the entire input is passed to the filter as a single long
+        string.
+
+      * `--null-input`/`-n`
+
+        Don't read any input at all! Instead, the filter is run once
+        using `null` as the input. This is useful when using jq as a
+        simple calculator or to construct JSON data from scratch.
+
+      * `--compact-output` / `-c`
+
+        By default, jq pretty-prints JSON output. Using this option
+        will result in more compact output by instead putting each
+        JSON object on a single line.
+
+      * `--ascii-output` / `-a`
+
+        jq usually outputs non-ASCII Unicode codepoints as UTF-8, even
+        if the input specified them as escape sequences (like
+        "\u03bc"). Using this option, you can force jq to produce pure
+        ASCII output with every non-ASCII character replaced with the
+        equivalent escape sequence.
+
+      * `--raw-output` / `-r`
+
+        With this option, if the filter's result is a string then it
+        will be written directly to standard output rather than being
+        formatted as a JSON string with quotes. This can be useful for
+        making jq filters talk to non-JSON-based systems.
+
+  - title: Basic filters
     entries:
       - title: "`.`"
         body: |

main.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <string.h>
+#include <ctype.h>
 #include "compile.h"
 #include "builtin.h"
 #include "jv.h"
@@ -12,17 +13,98 @@ static const char* progname;
 
 static void usage() {
   fprintf(stderr, "\njq - commandline JSON processor\n");
-  fprintf(stderr, "Usage: %s <jq filter>\n\n", progname);
-  fprintf(stderr, "For a description of how to write jq filters and\n");
-  fprintf(stderr, "why you might want to, see the jq documentation at\n");
-  fprintf(stderr, "http://stedolan.github.com/jq\n\n");
+  fprintf(stderr, "Usage: %s [options] <jq filter>\n\n", progname);
+  fprintf(stderr, "For a description of the command line options and\n");
+  fprintf(stderr, "how to write jq filters (and why you might want to)\n");
+  fprintf(stderr, "see the jq documentation at http://stedolan.github.com/jq\n\n");
   exit(1);
 }
 
+static void die() {
+  fprintf(stderr, "Use %s --help for help with command-line options,\n", progname);
+  fprintf(stderr, "or see the jq documentation at http://stedolan.github.com/jq\n");
+  exit(1);
+}
+
+
+
+
+static int isoptish(const char* text) {
+  return text[0] == '-' && (text[1] == '-' || isalpha(text[1]));
+}
+
+static int isoption(const char* text, char shortopt, const char* longopt) {
+  if (text[0] != '-') return 0;
+  if (strlen(text) == 2 && text[1] == shortopt) return 1;
+  if (text[1] == '-' && !strcmp(text+2, longopt)) return 1;
+  return 0;
+}
+
+enum {
+  SLURP = 1,
+  RAW_INPUT = 2,
+  PROVIDE_NULL = 4,
+
+  RAW_OUTPUT = 8,
+  COMPACT_OUTPUT = 16,
+  ASCII_OUTPUT = 32,
+};
+static int options = 0;
+static struct bytecode* bc;
+
+static void process(jv value) {
+  jq_init(bc, value);
+  jv result;
+  while (jv_is_valid(result = jq_next())) {
+    if ((options & RAW_OUTPUT) && jv_get_kind(result) == JV_KIND_STRING) {
+      fwrite(jv_string_value(result), 1, jv_string_length(jv_copy(result)), stdout);
+    } else {
+      int dumpopts = 0;
+      if (!(options & COMPACT_OUTPUT)) dumpopts |= JV_PRINT_PRETTY;
+      if (options & ASCII_OUTPUT) dumpopts |= JV_PRINT_ASCII;
+      jv_dump(result, dumpopts);
+    }
+    printf("\n");
+  }
+  jv_free(result);
+  jq_teardown();
+}
+
 int main(int argc, char* argv[]) {
   if (argc) progname = argv[0];
-  if (argc != 2 || !strcmp(argv[1], "--help") || !strcmp(argv[1], "--version")) usage();
-  struct bytecode* bc = jq_compile(argv[1]);
+
+  const char* program = 0;
+  for (int i=1; i<argc; i++) {
+    if (!isoptish(argv[i])) {
+      if (program) usage();
+      program = argv[i];
+    } else if (isoption(argv[i], 's', "slurp")) {
+      options |= SLURP;
+    } else if (isoption(argv[i], 'r', "raw-output")) {
+      options |= RAW_OUTPUT;
+    } else if (isoption(argv[i], 'c', "compact-output")) {
+      options |= COMPACT_OUTPUT;
+    } else if (isoption(argv[i], 'a', "ascii-output")) {
+      options |= ASCII_OUTPUT;
+    } else if (isoption(argv[i], 'R', "raw-input")) {
+      options |= RAW_INPUT;
+    } else if (isoption(argv[i], 'n', "null-input")) {
+      options |= PROVIDE_NULL;
+    } else if (isoption(argv[i], 'h', "help")) {
+      usage();
+    } else {
+      fprintf(stderr, "%s: Unknown option %s\n", progname, argv[i]);
+      die();
+    }
+  }
+  if (!program) usage();
+
+  if ((options & PROVIDE_NULL) && (options & (RAW_INPUT | SLURP))) {
+    fprintf(stderr, "%s: --null-input cannot be used with --raw-input or --slurp\n", program);
+    die();
+  }
+
+  bc = jq_compile(program);
   if (!bc) return 1;
 
 #if JQ_DEBUG
@@ -30,33 +112,59 @@ int main(int argc, char* argv[]) {
   printf("\n");
 #endif
 
-  struct jv_parser parser;
-  jv_parser_init(&parser);
-  while (!feof(stdin)) {
-    char buf[4096];
-    if (!fgets(buf, sizeof(buf), stdin)) buf[0] = 0;
-    jv_parser_set_buf(&parser, buf, strlen(buf), !feof(stdin));
-    jv value;
-    while (jv_is_valid((value = jv_parser_next(&parser)))) {
-      jq_init(bc, value);
-      jv result;
-      while (jv_is_valid(result = jq_next())) {
-        jv_dump(result, JV_PRINT_PRETTY);
-        printf("\n");
+  if (options & PROVIDE_NULL) {
+    process(jv_null());
+  } else {
+    jv slurped;
+    if (options & SLURP) slurped = jv_invalid();
+    int first = 1;
+    struct jv_parser parser;
+    jv_parser_init(&parser);
+    while (!feof(stdin)) {
+      char buf[4096];
+      if (!fgets(buf, sizeof(buf), stdin)) buf[0] = 0;
+      if (options & RAW_INPUT) {
+        int len = strlen(buf);
+        if (len > 0) {
+          if (options & SLURP) {
+            if (first) slurped = jv_string(buf);
+            else slurped = jv_string_concat(slurped, jv_string(buf));
+          } else {
+            if (buf[len-1] == '\n') buf[len-1] = 0;
+            process(jv_string(buf));
+          }
+        }
+      } else {
+        jv_parser_set_buf(&parser, buf, strlen(buf), !feof(stdin));
+        jv value;
+        while (jv_is_valid((value = jv_parser_next(&parser)))) {
+          if (options & SLURP) {
+            if (first) slurped = jv_array();
+            slurped = jv_array_append(slurped, value);
+          } else {
+            process(value);
+          }
+        }
+        if (jv_invalid_has_msg(jv_copy(value))) {
+          jv msg = jv_invalid_get_msg(value);
+          fprintf(stderr, "parse error: %s\n", jv_string_value(msg));
+          jv_free(msg);
+          break;
+        } else {
+          jv_free(value);
+        }
       }
-      jv_free(result);
-      jq_teardown();
+      first = 0;
     }
-    if (jv_invalid_has_msg(jv_copy(value))) {
-      jv msg = jv_invalid_get_msg(value);
-      fprintf(stderr, "parse error: %s\n", jv_string_value(msg));
-      jv_free(msg);
-      break;
-    } else {
-      jv_free(value);
+    jv_parser_free(&parser);
+    if (options & SLURP) {
+      if (jv_is_valid(slurped)) {
+        process(slurped);
+      } else {
+        jv_free(slurped);
+      }
     }
   }
-  jv_parser_free(&parser);
 
   bytecode_free(bc);
   return 0;