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--- cs_lang:c [2011/07/12 10:25] – created cedric
+++ cs_lang:c [2012/09/30 23:32] (current) – cedric
@@ Line 1: / Line 1: @@
+====== Learning C ======
+  * [[http://www.librarything.fr/work/3600740/book/62075147 | The C Programming Language]].
+====== Simple examples ======
+===== Hello World =====
 <code c>
 /* Hello World program */
@@ Line 8: / Line 15: @@
 {
     printf("Hello World");
+}
+</code>
+Compile and run the program:
+<code bash>
+$ gcc -Wall hello.c -o hello.out
+hello.c:6: warning: return type defaults to ‘int’
+hello.c: In function ‘main’:
+hello.c:10: warning: control reaches end of non-void function
+$ ./hello.out
+Hello World
+</code>
+===== Increment a number =====
+<code c>
+#include "stdio.h"
+char  line[100];
+int   value;
+int main()
+{
+    printf("Enter a value:");
+    fgets(line, sizeof(line), stdin);
+    sscanf(line, "%d", &value);
+    printf("Inc: %d\n", value + 1);
+    return 0;
 }
+</code>
+<code bash>
+$ gcc -Wall test1.c
+cedric@debian:~$ ./a.out
+Enter a value:41
+Inc: 42
+</code>
+==== Equivalent in python ====
+<code python>
+>>> def inc():
+...     value = raw_input("Enter a value:")
+...     print "Inc:", int(value)+1
+...
+>>> inc()
+Enter a value:41
+Inc: 42
+</code>
+===== Read a file =====
+<code c>
+#include <stdio.h>   /* required for file operations */
+FILE *fr;            /* declare the file pointer */
+main()
+{
+   char line[1024];
+   fr = fopen ("./file.txt", "rt");  /* open the file for reading */
+   /* "rt" means open the file for reading text */
+   while(fgets(line, 1024, fr) != NULL)
+   {
+         printf ("%s\n", line);
+   }
+   fclose(fr);  /* close the file prior to exiting the routine */
+}
+</code>
+==== Equivalent in python ====
+<code python>
+for line in open("./file.txt", "r"):
+    print line
 </code>