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>> file means stdout will be appended at the end of file. >>& file means both stdout and stderr will be appended at the end of file. < file means stdin will be read from file. << string is a here document. Stdin will read the following lines up to the one that matches string. Redirecting stderr alone isn't possible without the aid of a sub-shell.
The C programming language provides many standard library functions for file input and output.These functions make up the bulk of the C standard library header <stdio.h>. [1] The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s, [2] and officially became part of the Unix operating system in Version 7.
The reason for this is to distinguish between a file named '1' and stdout, i.e. cat file 2 >1 vs cat file 2 > & 1. In the first case, stderr is redirected to a file named ' 1 ' and in the second, stderr is redirected to stdout. Another useful capability is to redirect one standard file handle to another.
The “t” in tcsh comes from the “T” in TENEX, an operating system which inspired Ken Greer at Carnegie Mellon University, the author of tcsh, with its command-completion feature. [14] Greer began working on his code to implement Tenex-style file name completion in September 1975, finally merging it into the C shell in December 1981. [7]
Strings are passed to functions by passing a pointer to the first code unit. Since char * and wchar_t * are different types, the functions that process wide strings are different than the ones processing normal strings and have different names. String literals ("text" in the C source code) are converted to arrays during compilation. [2]
Some compilers (for example, GCC [8]) provide built-in versions of many of the functions in the C standard library; that is, the implementations of the functions are written into the compiled object file, and the program calls the built-in versions instead of the functions in the C library shared object file.
Despite this, the C code does not copy C stack frames, only Scheme objects, so it does not require knowledge of the C implementation. In full, the Scheme heap consists of the C stack as the nursery together with the two heaps required by the generational garbage collector. This approach gives the speed of the C stack for many operations, and it ...
The preprocessor provides some macro definitions automatically. The C standard specifies that __FILE__ expands to the name of the file being processed and __LINE__ expands to the number of the line that contains the directive. The following macro, DEBUGPRINT, formats and prints a message with the file name and line number.