http://snippets.dzone.com/posts Sun, 27 Jul 2008 03:00:47 GMT DZone Snippets: pipes code http://snippets.dzone.com/posts/show/4159 This little bash script shows how to use curl, grep, tail, sed and perl one-liners in order to compose a bleeding-edge twitter bot. <br />This one returns daily weather forecasts for Lisbon city based on the BBC weather forecast rss feed. <br /> <br /><code> <br />#! /bin/sh <br /> <br />#Goto here <br />here=/home/guillaume/Personal <br />cd $here <br /> <br />#BBC Lisbon weather id <br />id=0048 <br /> <br />#BBC weather RSS feed address <br />feed="http://feeds.bbc.co.uk/weather/feeds/rss/5day/world/${id}.xml" <br /> <br />#City <br />city=lisbon <br /> <br />#temporary file <br />file="weather${city}" <br /> <br />#Weather twitter bot <br />twitbot=weatherlisbon:******* <br /> <br />#Timestamp the log file <br />echo .>> $file.log <br />date >> $file.log <br /> <br />#Read the RSS feed and filter it <br />curl $feed | grep 'title' | tail -n 1 | perl -wlne'm/title>(.*)<\/title/i && print $1' | sed -e "s/&#xB0;//g" > $file.txt <br /> <br />#Read the forecast into a weather variable <br />read weather < $file.txt <br /> <br />#Twit the weather variable away <br />curl --basic --user $twitbot --data status="$weather" http://twitter.com/statuses/update.xml >> $file.log <br /></code> Mon, 18 Jun 2007 21:37:40 GMT http://snippets.dzone.com/posts/show/4159 griflet (guillaume riflet) http://snippets.dzone.com/posts/show/1134 I needed a simple popen2 implementation. This is similar to popen, but allows for bidirectional communication with the application being executed. Based on some other examples, I put this together. It makes for a good base. <br /> <br /><code> <br />#include <sys/types.h> <br />#include <fcntl.h> <br />#include <stdio.h> <br />#include <stdlib.h> <br />#include <unistd.h> <br /> <br />#define READ 0 <br />#define WRITE 1 <br /> <br />pid_t <br />popen2(const char *command, int *infp, int *outfp) <br />{ <br /> int p_stdin[2], p_stdout[2]; <br /> pid_t pid; <br /> <br /> if (pipe(p_stdin) != 0 || pipe(p_stdout) != 0) <br /> return -1; <br /> <br /> pid = fork(); <br /> <br /> if (pid < 0) <br /> return pid; <br /> else if (pid == 0) <br /> { <br /> close(p_stdin[WRITE]); <br /> dup2(p_stdin[READ], READ); <br /> close(p_stdout[READ]); <br /> dup2(p_stdout[WRITE], WRITE); <br /> <br /> execl("/bin/sh", "sh", "-c", command, NULL); <br /> perror("execl"); <br /> exit(1); <br /> } <br /> <br /> if (infp == NULL) <br /> close(p_stdin[WRITE]); <br /> else <br /> *infp = p_stdin[WRITE]; <br /> <br /> if (outfp == NULL) <br /> close(p_stdout[READ]); <br /> else <br /> *outfp = p_stdout[READ]; <br /> <br /> return pid; <br />} <br /></code> <br /> <br />Simple usage would be: <br /> <br /><code> <br />int <br />main(int argc, char **argv) <br />{ <br /> int infp, outfp; <br /> char buf[128]; <br /> <br /> if (popen2("sort", &infp, &outfp) <= 0) <br /> { <br /> printf("Unable to exec sort\n"); <br /> exit(1); <br /> } <br /> <br /> write(infp, "Z\n", 2); <br /> write(infp, "D\n", 2); <br /> write(infp, "A\n", 2); <br /> write(infp, "C\n", 2); <br /> close(infp); <br /> <br /> *buf = '\0'; <br /> read(outfp, buf, 128); <br /> <br /> printf("buf = '%s'\n", buf); <br /> <br /> return 0; <br />} <br /></code> Wed, 11 Jan 2006 04:40:00 GMT http://snippets.dzone.com/posts/show/1134 chipx86 (Christian Hammond)