.

.gitignore

@@ -0,0 +1 @@
+/build/

extension.c

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+#include <magic.h>
+#include <libowfat/errmsg.h>
+#include <libowfat/byte.h>
+#include <libowfat/str.h>
+
+#include "pipeshare.h"
+
+#define MAX(a,b) (a>b?a:b)
+
+#define failmagic(...) do {                                \
+    carp(__VA_ARGS__,": ",magic_error(magic));             \
+    return 0;                                              \
+  } while(0)
+
+int extension(int64 fd,char result[16])
+{
+  magic_t magic=magic_open(MAGIC_EXTENSION);
+  if(!magic) failmagic("initialize libmagic");
+  if(magic_load(magic,NULL)<0) failmagic("load magic database");
+  const char *extensions=magic_descriptor(magic,fd);
+  if(!extensions) failmagic("get magic data");
+
+  size_t l=MAX(str_chr(extensions,'/'),16);
+  byte_copy(result,l,extensions);
+  result[l]=0;
+  magic_close(magic);
+  if(str_equal(result,"???"))
+    str_copy(result,"txt");
+  return 1;
+}
+
+#undef failmagic

meson.build

@@ -0,0 +1,29 @@
+project(
+  'pipeshare', 'c',
+  default_options: [
+    'c_std=c99',
+    'warning_level=2',
+  ],
+)
+
+cc = meson.get_compiler('c')
+deps = [
+  cc.find_library('libowfat'),
+  dependency('libmagic'),
+]
+
+executable('pipeshare', files(
+  './pipeshare.c',
+  './send_stdin.c',
+  './extension.c',
+), dependencies:deps, install:true)
+
+executable('pipeshare-clean', files(
+  './pipeshare-clean.c',
+), dependencies:deps, install:true)
+
+
+install_man([
+  './pipeshare.1',
+  './pipeshare-clean.1',
+])

pipeshare-clean.1

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+.TH pipeshare 1
+.SH NAME
+pipeshare-clean \- remove old files
+.SH SYNOPSIS
+pipeshare-clean [-C dir]
+.SH OPTIONS
+\-C dir
+  chdir into dir at startup
+.SH DESCRIPTION
+if \-C is given, pipeshare-clean cd's into the specified
+directory.
+It then walks through all files that do not have a file
+extension(i.e. do not contain a dot in their name) and for
+each whose last chagne is older than 14 days, prompts the
+user whether to delete it or not. If it is marked for
+deletion, the file along with any other file starting with
+the same prefix(id) are deleted.
+.PP
+The confirmation prompt is used to avoid accidental deletion
+of files when pipeshare-clean is used from the wrong working
+directory.
+.SH "SEE ALSO"
+pipeshare(1)

pipeshare-clean.c

@@ -0,0 +1,89 @@
+#include <sys/stat.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <libowfat/errmsg.h>
+#include <libowfat/array.h>
+#include <limits.h>
+#include <libowfat/str.h>
+#include <libowfat/buffer.h>
+#include <time.h>
+
+#define dieusage() die(100,argv0," [-C dir]")
+#define dienoarg(OPT)                     \
+  do {                                    \
+    carp("missing argument for -"OPT);    \
+    dieusage();                           \
+  } while(0)
+
+static time_t now,expiration;
+
+static int prompt_confirm(char *file)
+{
+  char c;
+  buffer_puts(buffer_1,"remove ");
+  buffer_puts(buffer_1,file);
+  buffer_putsflush(buffer_1,"? [y/N]");
+  if (read(0,&c,1)<=0) return 0;
+  return c=='y' || c=='Y';
+}
+
+static void delete_shared(char *id)
+{
+  DIR *dir;
+  struct dirent *ent;
+  dir=opendir(".");
+  if (!dir) diesys(111,"opendir");
+  while ((ent=readdir(dir)))
+    if (str_start(ent->d_name,id))
+      unlink(ent->d_name);
+  closedir(dir);
+}
+
+static void run(void)
+{
+  DIR *dir;
+  struct dirent *ent;
+  struct stat st;
+  dir=opendir(".");
+  if (!dir) diesys(111,"opendir");
+  while ((ent=readdir(dir))) {
+    if (str_chr(ent->d_name,'.')!=str_len(ent->d_name))
+      continue;
+    if (stat(ent->d_name,&st)<0)
+      diesys(111,"stat ",ent->d_name);
+    /* ignore alias */
+    if (now-st.st_mtime > expiration) {
+      if (!prompt_confirm(ent->d_name))
+        continue;
+      buffer_putsflush(buffer_1,"\n");
+      delete_shared(ent->d_name);
+    }
+  }
+}
+
+int main(int argc, char **argv)
+{
+  int i;
+  char *dir=".";
+  errmsg_iam(*argv);
+  for (i=1;i<argc;i++) {
+    if (argv[i][0]!='-') break;
+    if (argv[i][1]=='-' && !argv[i][2]) break;
+    switch (argv[i][1]) {
+    case 'C':
+      if(!argv[++i]) dienoarg("C");
+      dir=argv[i];
+      break;
+    default: dieusage();
+    }
+  }
+  argc-=i; argv+=i;
+  
+  if (chdir(dir)<0)
+    diesys(100,"chdir ",dir);
+
+  time(&now);
+  /* 14 days */
+  expiration = 14*60*60*24;
+  run();
+}

pipeshare.1

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+.TH pipeshare 1
+.SH NAME
+pipeshare \- share files
+.SH SYNOPSIS
+pipeshare [-C dir] < FILE
+.SH OPTIONS
+\-C dir
+  chdir into dir at startup
+.SH DESCRIPTION
+if \-C is given, pipeshare cd's into the specified
+directory.
+It chooses a unique filename in the directory(called the id)
+and copys stdin into that files. Then it creates an
+"alias"-file that reuses the same filename but with an added
+extension. The extension is determined based on the MIME
+type of the file.
+.PP
+To delete old files, pipeshare-clean(1) may be used.
+.SH ENVIRONMENT
+WWWBASE
+  base url to print. e.g. https://example.org will make
+  pipeshare print https://example.org/r4nd0m.txt
+.SH "SEE ALSO"
+pipeshare-clean(1)

pipeshare.c

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+#define _XOPEN_SOURCE 500
+#include <libowfat/errmsg.h>
+#include <libowfat/str.h>
+#include <libowfat/buffer.h>
+#include <unistd.h>
+#include <alloca.h>
+#include <libgen.h>
+
+#include "pipeshare.h"
+
+#define dieusage() die(100,argv0," [-C dir]")
+#define dienoarg(OPT)                     \
+  do {                                    \
+    carp("missing argument for -"OPT);    \
+    dieusage();                           \
+  } while(0)
+
+static char *wwwbase=NULL;
+
+static int mkaliasfile(char *id,char ext[16])
+{
+  char *alias;
+  size_t l;
+  alias=alloca(str_len(id)+17);
+  l=str_copy(alias,id);
+  alias[l++]='.';
+  l+=str_copy(alias+l,ext);
+  alias[l]=0;
+  if(symlink(id,alias)<0) {
+    carpsys("symlink ",id," -> ",alias);
+    return 0;
+  }
+
+  return 1;
+}
+
+int main(int argc, char **argv)
+{
+  int i;
+  char *dir=".";
+  char tmp[]="./XXXXXX";
+  int tmpfd;
+  char ext[16];
+  errmsg_iam(*argv);
+  for (i=1;i<argc;i++) {
+    if (argv[i][0]!='-') break;
+    if (argv[i][1]=='-' && !argv[i][2]) break;
+    switch (argv[i][1]) {
+    case 'C':
+      if (!argv[++i]) dienoarg("C");
+      dir=argv[i];
+      break;
+    default: dieusage();
+    }
+  }
+  argc-=i; argv+=i;
+  if (argc!=0) dieusage();
+  wwwbase=getenv("WWWBASE");
+  if (!wwwbase) die(100,"WWWBASE not set");
+
+  if (chdir(dir)<0)
+    diesys(111,"chdir ",dir);
+
+  tmpfd=mkstemp(tmp);
+  if(tmpfd<0) diesys(111, "mkstemp in ", argv[0]);
+  if(!io_fd(tmpfd)
+   ||!io_fd(0)
+  ) {
+    unlink(tmp);
+    diesys(111,"io_fd");
+  }
+
+  if(!send_stdin(tmpfd)) {
+    unlink(tmp);
+    die(111,"copy stdin to ",tmp);
+  }
+
+  lseek(tmpfd,0,SEEK_SET);
+  if(!extension(tmpfd,ext)) {
+    carp("determine extension");
+    return 0;
+  }
+
+  if(!mkaliasfile(tmp,ext)) {
+    unlink(tmp);
+    die(111,"create alias with extension");
+  }
+
+  buffer_puts(buffer_1,wwwbase);
+  buffer_puts(buffer_1,"/");
+  buffer_puts(buffer_1,basename(tmp));
+  buffer_puts(buffer_1,".");
+  buffer_puts(buffer_1,ext);
+  buffer_putsflush(buffer_1,"\n");
+}

pipeshare.h

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+#ifndef PIPESHARE_H
+#define PIPESHARE_H
+
+#include <libowfat/io.h>
+
+int send_stdin(int64 fd);
+
+int extension(int64 fd,char result[16]);
+
+#endif

send_stdin.c

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+#include <libowfat/errmsg.h>
+
+#include "pipeshare.h"
+
+int send_stdin(int64 fd)
+{
+  char buf[8192];
+  int r;
+  uint64 readpos=0,writepos=0;
+  int eof=0;
+  for(;;){
+    if(eof && writepos>=readpos)break;
+    if(!eof && readpos < sizeof buf) {
+      r=io_tryread(0,buf+readpos,(sizeof buf)-readpos);
+      if(r<=-2){carpsys("read stdin");return 0;}
+      if(r==0)eof=1;
+      if(r>0)readpos+=r;
+    }
+    if(writepos<readpos){
+      r=io_trywrite(fd,buf+writepos,readpos-writepos);
+      if(r<=-2){carpsys("write");return 0;}
+      if(r>0){
+        writepos+=r;
+        if(writepos==readpos)
+          readpos=writepos=0;
+      }
+    }
+  }
+  return 1;
+}
+